diff --git a/src/LogExpert.UI/Controls/BufferedDataGridView.cs b/src/LogExpert.UI/Controls/BufferedDataGridView.cs
index c52e73bc..83dd2575 100644
--- a/src/LogExpert.UI/Controls/BufferedDataGridView.cs
+++ b/src/LogExpert.UI/Controls/BufferedDataGridView.cs
@@ -10,7 +10,7 @@
 namespace LogExpert.Dialogs;
 
 [SupportedOSPlatform("windows")]
-public partial class BufferedDataGridView : DataGridView
+internal partial class BufferedDataGridView : DataGridView
 {
     #region Fields
 
diff --git a/src/LogExpert.UI/Controls/ColorComboBox.cs b/src/LogExpert.UI/Controls/ColorComboBox.cs
index 2cc8dcd1..71feb634 100644
--- a/src/LogExpert.UI/Controls/ColorComboBox.cs
+++ b/src/LogExpert.UI/Controls/ColorComboBox.cs
@@ -4,7 +4,7 @@
 namespace LogExpert.UI.Controls;
 
 [SupportedOSPlatform("windows")]
-public class ColorComboBox : ComboBox
+internal class ColorComboBox : ComboBox
 {
     #region Fields
 
diff --git a/src/LogExpert.UI/Controls/DateTimeDragControl.cs b/src/LogExpert.UI/Controls/DateTimeDragControl.cs
index 676e9f86..0d4dd777 100644
--- a/src/LogExpert.UI/Controls/DateTimeDragControl.cs
+++ b/src/LogExpert.UI/Controls/DateTimeDragControl.cs
@@ -15,7 +15,7 @@ namespace LogExpert.Dialogs;
 /// The control raises events (ValueChanged, ValueDragged) when the date/time changes so that owner can react accordingly.
 /// </summary>
 [SupportedOSPlatform("windows")]
-public partial class DateTimeDragControl : UserControl
+internal partial class DateTimeDragControl : UserControl
 {
     #region Fields
 
diff --git a/src/LogExpert.UI/Controls/KnobControl.cs b/src/LogExpert.UI/Controls/KnobControl.cs
index b63eb5c4..f0893f18 100644
--- a/src/LogExpert.UI/Controls/KnobControl.cs
+++ b/src/LogExpert.UI/Controls/KnobControl.cs
@@ -5,7 +5,7 @@
 namespace LogExpert.UI.Controls;
 
 [SupportedOSPlatform("windows")]
-public partial class KnobControl : UserControl
+internal partial class KnobControl : UserControl
 {
     #region Fields
 
diff --git a/src/LogExpert.UI/Controls/LogCellEditingControl.cs b/src/LogExpert.UI/Controls/LogCellEditingControl.cs
index 316ed197..024bd30c 100644
--- a/src/LogExpert.UI/Controls/LogCellEditingControl.cs
+++ b/src/LogExpert.UI/Controls/LogCellEditingControl.cs
@@ -3,7 +3,7 @@
 namespace LogExpert.UI.Controls;
 
 [SupportedOSPlatform("windows")]
-public class LogCellEditingControl : DataGridViewTextBoxEditingControl
+internal class LogCellEditingControl : DataGridViewTextBoxEditingControl
 {
     #region Public methods
 
diff --git a/src/LogExpert.UI/Controls/LogGridCell.cs b/src/LogExpert.UI/Controls/LogGridCell.cs
index fe870e1b..e9954a17 100644
--- a/src/LogExpert.UI/Controls/LogGridCell.cs
+++ b/src/LogExpert.UI/Controls/LogGridCell.cs
@@ -3,7 +3,7 @@
 
 namespace LogExpert.UI.Controls;
 
-public class LogGridCell : DataGridViewTextBoxCell
+internal class LogGridCell : DataGridViewTextBoxCell
 {
     #region Properties
 
diff --git a/src/LogExpert.UI/Controls/LogTextColumn.cs b/src/LogExpert.UI/Controls/LogTextColumn.cs
index 3f2e44b7..c0054b30 100644
--- a/src/LogExpert.UI/Controls/LogTextColumn.cs
+++ b/src/LogExpert.UI/Controls/LogTextColumn.cs
@@ -2,7 +2,7 @@
 
 namespace LogExpert.UI.Controls;
 
-public class LogTextColumn : DataGridViewColumn
+internal class LogTextColumn : DataGridViewColumn
 {
     #region cTor
 
diff --git a/src/LogExpert.UI/Controls/LogWindow/LogWindow.cs b/src/LogExpert.UI/Controls/LogWindow/LogWindow.cs
index 34e04cc6..b1d52dbb 100644
--- a/src/LogExpert.UI/Controls/LogWindow/LogWindow.cs
+++ b/src/LogExpert.UI/Controls/LogWindow/LogWindow.cs
@@ -25,7 +25,7 @@ namespace LogExpert.UI.Controls.LogWindow;
 
 //TODO: Implemented 4 interfaces explicitly. Find them by searching: ILogWindow.<method name>
 [SupportedOSPlatform("windows")]
-public partial class LogWindow : DockContent, ILogPaintContextUI, ILogView, ILogWindow
+internal partial class LogWindow : DockContent, ILogPaintContextUI, ILogView, ILogWindow
 {
     #region Fields
 
diff --git a/src/LogExpert.UI/Controls/LogWindow/LogWindowPublic.cs b/src/LogExpert.UI/Controls/LogWindow/LogWindowPublic.cs
index 9fce6a8c..03c37a77 100644
--- a/src/LogExpert.UI/Controls/LogWindow/LogWindowPublic.cs
+++ b/src/LogExpert.UI/Controls/LogWindow/LogWindowPublic.cs
@@ -1,7 +1,6 @@
 using System.Text;
 
 using LogExpert.Core.Classes;
-using LogExpert.Core.Classes.Bookmark;
 using LogExpert.Core.Classes.Columnizer;
 using LogExpert.Core.Classes.Filter;
 using LogExpert.Core.Classes.Highlight;
diff --git a/src/LogExpert.UI/Controls/LogWindow/RangeFinder.cs b/src/LogExpert.UI/Controls/LogWindow/RangeFinder.cs
index 8fe836d7..4a46be2a 100644
--- a/src/LogExpert.UI/Controls/LogWindow/RangeFinder.cs
+++ b/src/LogExpert.UI/Controls/LogWindow/RangeFinder.cs
@@ -12,7 +12,7 @@ namespace LogExpert.UI.Controls.LogWindow;
 /// <summary>
 /// Delivers the range (from..to) that matches the current range filter settings starting from a given line.
 /// </summary>
-public class RangeFinder(FilterParams filterParams, ColumnizerCallback callback)
+internal class RangeFinder(FilterParams filterParams, ColumnizerCallback callback)
 {
     #region Fields
 
diff --git a/src/LogExpert.UI/Controls/LogWindow/TimeSyncList.cs b/src/LogExpert.UI/Controls/LogWindow/TimeSyncList.cs
index 5cf5a90c..fe51937b 100644
--- a/src/LogExpert.UI/Controls/LogWindow/TimeSyncList.cs
+++ b/src/LogExpert.UI/Controls/LogWindow/TimeSyncList.cs
@@ -5,7 +5,7 @@ namespace LogExpert.UI.Controls.LogWindow;
 /// <summary>
 /// Holds all windows which are in sync via timestamp
 /// </summary>
-public class TimeSyncList
+internal class TimeSyncList
 {
     #region Fields
 
diff --git a/src/LogExpert.UI/Dialogs/AboutBox.cs b/src/LogExpert.UI/Dialogs/AboutBox.cs
index 632dd07c..471d836f 100644
--- a/src/LogExpert.UI/Dialogs/AboutBox.cs
+++ b/src/LogExpert.UI/Dialogs/AboutBox.cs
@@ -1,4 +1,4 @@
-using LogExpert.Core.Classes;
+using LogExpert.Core.Classes;
 
 using Newtonsoft.Json;
 
@@ -9,7 +9,7 @@
 namespace LogExpert.UI.Dialogs;
 
 [SupportedOSPlatform("windows")]
-public partial class AboutBox : Form
+internal partial class AboutBox : Form
 {
     #region Fields
 
diff --git a/src/LogExpert.UI/Dialogs/BookmarkCommentDlg.cs b/src/LogExpert.UI/Dialogs/BookmarkCommentDlg.cs
index ece0c852..7949c604 100644
--- a/src/LogExpert.UI/Dialogs/BookmarkCommentDlg.cs
+++ b/src/LogExpert.UI/Dialogs/BookmarkCommentDlg.cs
@@ -1,9 +1,9 @@
-using System.Runtime.Versioning;
+using System.Runtime.Versioning;
 
 namespace LogExpert.Dialogs;
 
 [SupportedOSPlatform("windows")]
-public partial class BookmarkCommentDlg : Form
+internal partial class BookmarkCommentDlg : Form
 {
     #region cTor
 
diff --git a/src/LogExpert.UI/Dialogs/BookmarkWindow.cs b/src/LogExpert.UI/Dialogs/BookmarkWindow.cs
index 0ee8d848..c347a4c6 100644
--- a/src/LogExpert.UI/Dialogs/BookmarkWindow.cs
+++ b/src/LogExpert.UI/Dialogs/BookmarkWindow.cs
@@ -16,7 +16,7 @@ namespace LogExpert.Dialogs;
 
 //TODO can be moved to Logexpert.UI if the PaintHelper has been refactored
 [SupportedOSPlatform("windows")]
-public partial class BookmarkWindow : DockContent, ISharedToolWindow, IBookmarkView
+internal partial class BookmarkWindow : DockContent, ISharedToolWindow, IBookmarkView
 {
     #region Fields
 
diff --git a/src/LogExpert.UI/Dialogs/ChooseIconDlg.cs b/src/LogExpert.UI/Dialogs/ChooseIconDlg.cs
index bee7a594..229f18e8 100644
--- a/src/LogExpert.UI/Dialogs/ChooseIconDlg.cs
+++ b/src/LogExpert.UI/Dialogs/ChooseIconDlg.cs
@@ -4,7 +4,7 @@
 namespace LogExpert.UI.Dialogs;
 
 [SupportedOSPlatform("windows")]
-public partial class ChooseIconDlg : Form
+internal partial class ChooseIconDlg : Form
 {
     #region Fields
 
diff --git a/src/LogExpert.UI/Dialogs/FilterColumnChooser.cs b/src/LogExpert.UI/Dialogs/FilterColumnChooser.cs
index 4a62edb8..1aea2b15 100644
--- a/src/LogExpert.UI/Dialogs/FilterColumnChooser.cs
+++ b/src/LogExpert.UI/Dialogs/FilterColumnChooser.cs
@@ -1,11 +1,11 @@
-using LogExpert.Core.Classes.Filter;
+using LogExpert.Core.Classes.Filter;
 
 using System.Runtime.Versioning;
 
 namespace LogExpert.UI.Dialogs;
 
 [SupportedOSPlatform("windows")]
-public partial class FilterColumnChooser : Form
+internal partial class FilterColumnChooser : Form
 {
     #region Fields
 
diff --git a/src/LogExpert.UI/Dialogs/GotoLineDialog.cs b/src/LogExpert.UI/Dialogs/GotoLineDialog.cs
index 123b1ca1..8b7d0b36 100644
--- a/src/LogExpert.UI/Dialogs/GotoLineDialog.cs
+++ b/src/LogExpert.UI/Dialogs/GotoLineDialog.cs
@@ -1,9 +1,9 @@
-using System.Runtime.Versioning;
+using System.Runtime.Versioning;
 
 namespace LogExpert.UI.Dialogs;
 
 [SupportedOSPlatform("windows")]
-public partial class GotoLineDialog : Form
+internal partial class GotoLineDialog : Form
 {
     #region Fields
 
diff --git a/src/LogExpert.UI/Dialogs/ImportSettingsDialog.cs b/src/LogExpert.UI/Dialogs/ImportSettingsDialog.cs
index 5d66a75b..e7200fb4 100644
--- a/src/LogExpert.UI/Dialogs/ImportSettingsDialog.cs
+++ b/src/LogExpert.UI/Dialogs/ImportSettingsDialog.cs
@@ -1,11 +1,11 @@
-using LogExpert.Core.Config;
+using LogExpert.Core.Config;
 
 using System.Runtime.Versioning;
 
 namespace LogExpert.UI.Dialogs;
 
 [SupportedOSPlatform("windows")]
-public partial class ImportSettingsDialog : Form
+internal partial class ImportSettingsDialog : Form
 {
     #region cTor
 
diff --git a/src/LogExpert.UI/Dialogs/KeywordActionDlg.cs b/src/LogExpert.UI/Dialogs/KeywordActionDlg.cs
index b34dca5b..dbc508f0 100644
--- a/src/LogExpert.UI/Dialogs/KeywordActionDlg.cs
+++ b/src/LogExpert.UI/Dialogs/KeywordActionDlg.cs
@@ -1,11 +1,11 @@
-using LogExpert.Core.Classes.Highlight;
+using LogExpert.Core.Classes.Highlight;
 
 using System.Runtime.Versioning;
 
 namespace LogExpert.UI.Dialogs;
 
 [SupportedOSPlatform("windows")]
-public partial class KeywordActionDlg : Form
+internal partial class KeywordActionDlg : Form
 {
     #region Fields
 
diff --git a/src/LogExpert.UI/Dialogs/LogTabWindow/HighlightDialog.cs b/src/LogExpert.UI/Dialogs/LogTabWindow/HighlightDialog.cs
index 8a150e27..fa1e3b01 100644
--- a/src/LogExpert.UI/Dialogs/LogTabWindow/HighlightDialog.cs
+++ b/src/LogExpert.UI/Dialogs/LogTabWindow/HighlightDialog.cs
@@ -12,7 +12,7 @@
 namespace LogExpert.Dialogs;
 
 [SupportedOSPlatform("windows")]
-public partial class HighlightDialog : Form
+internal partial class HighlightDialog : Form
 {
     private static readonly ILogger _logger = LogManager.GetCurrentClassLogger();
 
diff --git a/src/LogExpert.UI/Dialogs/LogTabWindow/LogTabWindow.cs b/src/LogExpert.UI/Dialogs/LogTabWindow/LogTabWindow.cs
index 43742412..6ae4d6e3 100644
--- a/src/LogExpert.UI/Dialogs/LogTabWindow/LogTabWindow.cs
+++ b/src/LogExpert.UI/Dialogs/LogTabWindow/LogTabWindow.cs
@@ -16,7 +16,7 @@ namespace LogExpert.UI.Controls.LogTabWindow;
 // Data shared over all LogTabWindow instances
 //TODO: Can we get rid of this class?
 [SupportedOSPlatform("windows")]
-public partial class LogTabWindow : Form, ILogTabWindow
+internal partial class LogTabWindow : Form, ILogTabWindow
 {
     #region Fields
 
@@ -198,7 +198,7 @@ public void ChangeTheme (Control.ControlCollection container)
                     {
                         for (var x = 0; x < item.DropDownItems.Count; x++)
                         {
-                            ToolStripItem children = item.DropDownItems[x];
+                            var children = item.DropDownItems[x];
                             children.ForeColor = ColorMode.ForeColor;
                             children.BackColor = ColorMode.MenuBackgroundColor;
 
@@ -206,7 +206,7 @@ public void ChangeTheme (Control.ControlCollection container)
                             {
                                 for (var y = 0; y < toolstripDropDownItem.DropDownItems.Count; y++)
                                 {
-                                    ToolStripItem subChildren = toolstripDropDownItem.DropDownItems[y];
+                                    var subChildren = toolstripDropDownItem.DropDownItems[y];
                                     subChildren.ForeColor = ColorMode.ForeColor;
                                     subChildren.BackColor = ColorMode.MenuBackgroundColor;
                                 }
@@ -237,7 +237,7 @@ public void ChangeTheme (Control.ControlCollection container)
         // Tabs menu
         for (var y = 0; y < tabContextMenuStrip.Items.Count; y++)
         {
-            ToolStripItem item = tabContextMenuStrip.Items[y];
+            var item = tabContextMenuStrip.Items[y];
             item.ForeColor = ColorMode.ForeColor;
             item.BackColor = ColorMode.MenuBackgroundColor;
         }
diff --git a/src/LogExpert.UI/Dialogs/LogTabWindow/LogTabWindowEventHandlers.cs b/src/LogExpert.UI/Dialogs/LogTabWindow/LogTabWindowEventHandlers.cs
index 3b0dc376..16e7ed7e 100644
--- a/src/LogExpert.UI/Dialogs/LogTabWindow/LogTabWindowEventHandlers.cs
+++ b/src/LogExpert.UI/Dialogs/LogTabWindow/LogTabWindowEventHandlers.cs
@@ -9,14 +9,14 @@
 using LogExpert.Core.Entities;
 using LogExpert.Core.EventArguments;
 using LogExpert.Dialogs;
-using LogExpert.UI.Controls.LogWindow;
 using LogExpert.UI.Dialogs;
+using LogExpert.UI.Extensions.LogWindow;
 
 using WeifenLuo.WinFormsUI.Docking;
 
 namespace LogExpert.UI.Controls.LogTabWindow;
 
-public partial class LogTabWindow
+internal partial class LogTabWindow
 {
     #region Events handler
 
diff --git a/src/LogExpert.UI/Dialogs/LogTabWindow/LogTabWindowPrivate.cs b/src/LogExpert.UI/Dialogs/LogTabWindow/LogTabWindowPrivate.cs
index 68fcff65..8ad87e27 100644
--- a/src/LogExpert.UI/Dialogs/LogTabWindow/LogTabWindowPrivate.cs
+++ b/src/LogExpert.UI/Dialogs/LogTabWindow/LogTabWindowPrivate.cs
@@ -21,7 +21,7 @@
 
 namespace LogExpert.UI.Controls.LogTabWindow;
 
-public partial class LogTabWindow
+internal partial class LogTabWindow
 {
     #region Private Methods
 
diff --git a/src/LogExpert.UI/Dialogs/LogTabWindow/LogTabWindowPublic.cs b/src/LogExpert.UI/Dialogs/LogTabWindow/LogTabWindowPublic.cs
index eb4745ac..25000414 100644
--- a/src/LogExpert.UI/Dialogs/LogTabWindow/LogTabWindowPublic.cs
+++ b/src/LogExpert.UI/Dialogs/LogTabWindow/LogTabWindowPublic.cs
@@ -15,7 +15,7 @@
 
 namespace LogExpert.UI.Controls.LogTabWindow;
 
-public partial class LogTabWindow
+internal partial class LogTabWindow
 {
     #region Public methods
 
diff --git a/src/LogExpert.UI/Dialogs/MultiFileMaskDialog.cs b/src/LogExpert.UI/Dialogs/MultiFileMaskDialog.cs
index 8b2203cf..6bbf4b12 100644
--- a/src/LogExpert.UI/Dialogs/MultiFileMaskDialog.cs
+++ b/src/LogExpert.UI/Dialogs/MultiFileMaskDialog.cs
@@ -1,9 +1,9 @@
-using System.Runtime.Versioning;
+using System.Runtime.Versioning;
 
 namespace LogExpert.UI.Dialogs;
 
 [SupportedOSPlatform("windows")]
-public partial class MultiFileMaskDialog : Form
+internal partial class MultiFileMaskDialog : Form
 {
     #region Fields
 
diff --git a/src/LogExpert.UI/Dialogs/MultiLoadRequestDialog.cs b/src/LogExpert.UI/Dialogs/MultiLoadRequestDialog.cs
index b53360fd..0e311a0e 100644
--- a/src/LogExpert.UI/Dialogs/MultiLoadRequestDialog.cs
+++ b/src/LogExpert.UI/Dialogs/MultiLoadRequestDialog.cs
@@ -1,9 +1,9 @@
-using System.Runtime.Versioning;
+using System.Runtime.Versioning;
 
 namespace LogExpert.UI.Dialogs;
 
 [SupportedOSPlatform("windows")]
-public partial class MultiLoadRequestDialog : Form
+internal partial class MultiLoadRequestDialog : Form
 {
     #region cTor
 
diff --git a/src/LogExpert.UI/Dialogs/OpenUriDialog.cs b/src/LogExpert.UI/Dialogs/OpenUriDialog.cs
index 290a2471..0b9f8cd7 100644
--- a/src/LogExpert.UI/Dialogs/OpenUriDialog.cs
+++ b/src/LogExpert.UI/Dialogs/OpenUriDialog.cs
@@ -1,9 +1,9 @@
-using System.Runtime.Versioning;
+using System.Runtime.Versioning;
 
 namespace LogExpert.UI.Dialogs;
 
 [SupportedOSPlatform("windows")]
-public partial class OpenUriDialog : Form
+internal partial class OpenUriDialog : Form
 {
     #region Fields
 
diff --git a/src/LogExpert.UI/Dialogs/ParamRequesterDialog.cs b/src/LogExpert.UI/Dialogs/ParamRequesterDialog.cs
index ef272593..263a8a71 100644
--- a/src/LogExpert.UI/Dialogs/ParamRequesterDialog.cs
+++ b/src/LogExpert.UI/Dialogs/ParamRequesterDialog.cs
@@ -3,7 +3,7 @@
 namespace LogExpert.Dialogs;
 
 [SupportedOSPlatform("windows")]
-public partial class ParamRequesterDialog : Form
+internal partial class ParamRequesterDialog : Form
 {
     #region Fields
 
diff --git a/src/LogExpert.UI/Dialogs/ProjectLoadDlg.cs b/src/LogExpert.UI/Dialogs/ProjectLoadDlg.cs
index 95ca661d..5d268884 100644
--- a/src/LogExpert.UI/Dialogs/ProjectLoadDlg.cs
+++ b/src/LogExpert.UI/Dialogs/ProjectLoadDlg.cs
@@ -1,11 +1,11 @@
-using LogExpert.Core.Enums;
+using LogExpert.Core.Enums;
 
 using System.Runtime.Versioning;
 
 namespace LogExpert.Dialogs;
 
 [SupportedOSPlatform("windows")]
-public partial class ProjectLoadDlg : Form
+internal partial class ProjectLoadDlg : Form
 {
     #region Fields
 
diff --git a/src/LogExpert.UI/Dialogs/RegexHelperDialog.cs b/src/LogExpert.UI/Dialogs/RegexHelperDialog.cs
index 64c99a9f..ac7df7c5 100644
--- a/src/LogExpert.UI/Dialogs/RegexHelperDialog.cs
+++ b/src/LogExpert.UI/Dialogs/RegexHelperDialog.cs
@@ -4,7 +4,7 @@
 namespace LogExpert.UI.Dialogs;
 
 [SupportedOSPlatform("windows")]
-public partial class RegexHelperDialog : Form
+internal partial class RegexHelperDialog : Form
 {
     #region Fields
 
diff --git a/src/LogExpert.UI/Dialogs/SearchDialog.cs b/src/LogExpert.UI/Dialogs/SearchDialog.cs
index f1e09da9..9ae87f17 100644
--- a/src/LogExpert.UI/Dialogs/SearchDialog.cs
+++ b/src/LogExpert.UI/Dialogs/SearchDialog.cs
@@ -7,7 +7,7 @@
 namespace LogExpert.Dialogs;
 
 [SupportedOSPlatform("windows")]
-public partial class SearchDialog : Form
+internal partial class SearchDialog : Form
 {
     #region Fields
 
diff --git a/src/LogExpert.UI/Dialogs/SearchProgressDialog.cs b/src/LogExpert.UI/Dialogs/SearchProgressDialog.cs
index 5fd7a6be..5d1f8deb 100644
--- a/src/LogExpert.UI/Dialogs/SearchProgressDialog.cs
+++ b/src/LogExpert.UI/Dialogs/SearchProgressDialog.cs
@@ -1,9 +1,9 @@
-using System.Runtime.Versioning;
+using System.Runtime.Versioning;
 
 namespace LogExpert.UI.Dialogs;
 
 [SupportedOSPlatform("windows")]
-public partial class SearchProgressDialog : Form
+internal partial class SearchProgressDialog : Form
 {
     #region Fields
 
diff --git a/src/LogExpert.UI/Dialogs/TabRenameDialog.cs b/src/LogExpert.UI/Dialogs/TabRenameDialog.cs
index 3a7a5391..2f2455db 100644
--- a/src/LogExpert.UI/Dialogs/TabRenameDialog.cs
+++ b/src/LogExpert.UI/Dialogs/TabRenameDialog.cs
@@ -1,9 +1,9 @@
-using System.Runtime.Versioning;
+using System.Runtime.Versioning;
 
 namespace LogExpert.UI.Dialogs;
 
 [SupportedOSPlatform("windows")]
-public partial class TabRenameDialog : Form
+internal partial class TabRenameDialog : Form
 {
     #region cTor
 
diff --git a/src/LogExpert.UI/Entities/WindowFileEntry.cs b/src/LogExpert.UI/Entities/WindowFileEntry.cs
index 761c5c40..842dfd41 100644
--- a/src/LogExpert.UI/Entities/WindowFileEntry.cs
+++ b/src/LogExpert.UI/Entities/WindowFileEntry.cs
@@ -7,7 +7,7 @@ namespace LogExpert.UI.Entities;
 /// <summary>
 /// Represents a log file and its window. Used as a kind of handle for menus or list of open files.
 /// </summary>
-public class WindowFileEntry (LogWindow logWindow)
+internal class WindowFileEntry (LogWindow logWindow)
 {
     #region Fields
 
diff --git a/src/LogExpert.Core/Classes/Bookmark/BookmarkExporter.cs b/src/LogExpert.UI/Extensions/BookmarkExporter.cs
similarity index 84%
rename from src/LogExpert.Core/Classes/Bookmark/BookmarkExporter.cs
rename to src/LogExpert.UI/Extensions/BookmarkExporter.cs
index 2100f803..fbf2f660 100644
--- a/src/LogExpert.Core/Classes/Bookmark/BookmarkExporter.cs
+++ b/src/LogExpert.UI/Extensions/BookmarkExporter.cs
@@ -1,6 +1,8 @@
-namespace LogExpert.Core.Classes.Bookmark;
+using LogExpert.Core.Entities;
 
-public static class BookmarkExporter
+namespace LogExpert.UI.Extensions;
+
+internal static class BookmarkExporter
 {
     #region Fields
 
@@ -10,13 +12,13 @@ public static class BookmarkExporter
 
     #region Public methods
 
-    public static void ExportBookmarkList (SortedList<int, Entities.Bookmark> bookmarkList, string logfileName,
+    public static void ExportBookmarkList (SortedList<int, Bookmark> bookmarkList, string logfileName,
         string fileName)
     {
         FileStream fs = new(fileName, FileMode.Create, FileAccess.Write);
         StreamWriter writer = new(fs);
         writer.WriteLine("Log file name;Line number;Comment");
-        foreach (Entities.Bookmark bookmark in bookmarkList.Values)
+        foreach (var bookmark in bookmarkList.Values)
         {
             var line = $"{logfileName};{bookmark.LineNum};{bookmark.Text.Replace(replacementForNewLine, @"\" + replacementForNewLine, StringComparison.OrdinalIgnoreCase).Replace("\r\n", replacementForNewLine, StringComparison.OrdinalIgnoreCase)}";
             writer.WriteLine(line);
@@ -25,7 +27,7 @@ public static void ExportBookmarkList (SortedList<int, Entities.Bookmark> bookma
         fs.Close();
     }
 
-    public static void ImportBookmarkList (string logfileName, string fileName, SortedList<int, Entities.Bookmark> bookmarkList)
+    public static void ImportBookmarkList (string logfileName, string fileName, SortedList<int, Bookmark> bookmarkList)
     {
         using FileStream fs = new(fileName, FileMode.Open, FileAccess.Read);
         using StreamReader reader = new(fs);
@@ -51,7 +53,7 @@ public static void ImportBookmarkList (string logfileName, string fileName, Sort
 
                 if (int.TryParse(lineStr, out var lineNum))
                 {
-                    Entities.Bookmark bookmark = new(lineNum, comment);
+                    Bookmark bookmark = new(lineNum, comment);
                     bookmarkList.Add(lineNum, bookmark);
                 }
                 else
diff --git a/src/LogExpert.UI/Extensions/ComboBoxExtensions.cs b/src/LogExpert.UI/Extensions/ComboBoxExtensions.cs
index 90d7d31e..9cd24a7a 100644
--- a/src/LogExpert.UI/Extensions/ComboBoxExtensions.cs
+++ b/src/LogExpert.UI/Extensions/ComboBoxExtensions.cs
@@ -1,9 +1,9 @@
-using System.Runtime.Versioning;
+using System.Runtime.Versioning;
 
 namespace LogExpert.UI.Extensions;
 
 [SupportedOSPlatform("windows")]
-public static class ComboBoxExtensions
+internal static class ComboBoxExtensions
 {
     /// <seealso href="https://stackoverflow.com/a/4842576/1987788"/>
     public static int GetMaxTextWidth(this ComboBox comboBox)
diff --git a/src/LogExpert.UI/Extensions/Forms/LineToolStripSeparatorExtension.cs b/src/LogExpert.UI/Extensions/Forms/LineToolStripSeparatorExtension.cs
index 4c30c9a4..69fb69c6 100644
--- a/src/LogExpert.UI/Extensions/Forms/LineToolStripSeparatorExtension.cs
+++ b/src/LogExpert.UI/Extensions/Forms/LineToolStripSeparatorExtension.cs
@@ -1,11 +1,11 @@
-using LogExpert.Core.Config;
+using LogExpert.Core.Config;
 
 using System.Runtime.Versioning;
 
 namespace LogExpert.UI.Extensions.Forms;
 
 [SupportedOSPlatform("windows")]
-public class LineToolStripSeparatorExtension : ToolStripSeparator
+internal class LineToolStripSeparatorExtension : ToolStripSeparator
 {
     public LineToolStripSeparatorExtension()
     {
diff --git a/src/LogExpert.UI/Extensions/Forms/MenuSelectedColors.cs b/src/LogExpert.UI/Extensions/Forms/MenuSelectedColors.cs
index 5e6a81bd..bc3544e5 100644
--- a/src/LogExpert.UI/Extensions/Forms/MenuSelectedColors.cs
+++ b/src/LogExpert.UI/Extensions/Forms/MenuSelectedColors.cs
@@ -1,11 +1,11 @@
-using LogExpert.Core.Config;
+using LogExpert.Core.Config;
 
 using System.Runtime.Versioning;
 
 namespace LogExpert.UI.Extensions.Forms;
 
 [SupportedOSPlatform("windows")]
-public class MenuSelectedColors : ProfessionalColorTable
+internal class MenuSelectedColors : ProfessionalColorTable
 {
     public override Color ImageMarginGradientBegin => ColorMode.MenuBackgroundColor;
 
diff --git a/src/LogExpert.UI/Extensions/Forms/MenuStripExtension.cs b/src/LogExpert.UI/Extensions/Forms/MenuStripExtension.cs
index 1d4d16ca..e54a1796 100644
--- a/src/LogExpert.UI/Extensions/Forms/MenuStripExtension.cs
+++ b/src/LogExpert.UI/Extensions/Forms/MenuStripExtension.cs
@@ -1,9 +1,9 @@
-using System.Runtime.Versioning;
+using System.Runtime.Versioning;
 
 namespace LogExpert.UI.Extensions.Forms;
 
 [SupportedOSPlatform("windows")]
-public class ExtendedMenuStripRenderer : ToolStripProfessionalRenderer
+internal class ExtendedMenuStripRenderer : ToolStripProfessionalRenderer
 {
     public ExtendedMenuStripRenderer() : base(new MenuSelectedColors()) { }
 }
diff --git a/src/LogExpert.UI/Extensions/Forms/MenuToolStripSeparatorExtension.cs b/src/LogExpert.UI/Extensions/Forms/MenuToolStripSeparatorExtension.cs
index 82e44e39..3f5f26f1 100644
--- a/src/LogExpert.UI/Extensions/Forms/MenuToolStripSeparatorExtension.cs
+++ b/src/LogExpert.UI/Extensions/Forms/MenuToolStripSeparatorExtension.cs
@@ -1,11 +1,11 @@
-using LogExpert.Core.Config;
+using LogExpert.Core.Config;
 
 using System.Runtime.Versioning;
 
 namespace LogExpert.UI.Extensions.Forms;
 
 [SupportedOSPlatform("windows")]
-public class MenuToolStripSeparatorExtension : ToolStripSeparator
+internal class MenuToolStripSeparatorExtension : ToolStripSeparator
 {
     public MenuToolStripSeparatorExtension()
     {
diff --git a/src/LogExpert.UI/Extensions/Forms/ToolStripRendererExtension.cs b/src/LogExpert.UI/Extensions/Forms/ToolStripRendererExtension.cs
index 5b85f845..191d5988 100644
--- a/src/LogExpert.UI/Extensions/Forms/ToolStripRendererExtension.cs
+++ b/src/LogExpert.UI/Extensions/Forms/ToolStripRendererExtension.cs
@@ -1,9 +1,9 @@
-using System.Runtime.Versioning;
+using System.Runtime.Versioning;
 
 namespace LogExpert.UI.Extensions.Forms;
 
 [SupportedOSPlatform("windows")]
-public class ToolStripRendererExtension : ToolStripSystemRenderer
+internal class ToolStripRendererExtension : ToolStripSystemRenderer
 {
     public ToolStripRendererExtension() { }
 
diff --git a/src/LogExpert.UI/Controls/LogWindow/AbstractLogTabWindow.cs b/src/LogExpert.UI/Extensions/LogWindow/AbstractLogTabWindow.cs
similarity index 67%
rename from src/LogExpert.UI/Controls/LogWindow/AbstractLogTabWindow.cs
rename to src/LogExpert.UI/Extensions/LogWindow/AbstractLogTabWindow.cs
index 2a7caae9..664f4279 100644
--- a/src/LogExpert.UI/Controls/LogWindow/AbstractLogTabWindow.cs
+++ b/src/LogExpert.UI/Extensions/LogWindow/AbstractLogTabWindow.cs
@@ -1,9 +1,9 @@
 using System.Runtime.Versioning;
 
 using LogExpert.Core.Interface;
-using LogExpert.UI.Dialogs.LogTabWindow;
+using LogExpert.UI.Controls.LogTabWindow;
 
-namespace LogExpert.UI.Controls.LogWindow;
+namespace LogExpert.UI.Extensions.LogWindow;
 
 public abstract class AbstractLogTabWindow ()
 {
@@ -12,6 +12,6 @@ public abstract class AbstractLogTabWindow ()
     [SupportedOSPlatform("windows")]
     public static ILogTabWindow Create (string[] fileNames, int instanceNumber, bool showInstanceNumbers, IConfigManager configManager)
     {
-        return new LogTabWindow.LogTabWindow(fileNames, instanceNumber, showInstanceNumbers, configManager);
+        return new LogTabWindow(fileNames, instanceNumber, showInstanceNumbers, configManager);
     }
 }
\ No newline at end of file
diff --git a/src/LogExpert.UI/Controls/LogWindow/StaticLogTabWindowData.cs b/src/LogExpert.UI/Extensions/LogWindow/StaticLogTabWindowData.cs
similarity index 79%
rename from src/LogExpert.UI/Controls/LogWindow/StaticLogTabWindowData.cs
rename to src/LogExpert.UI/Extensions/LogWindow/StaticLogTabWindowData.cs
index 88e8e1bf..cc356eb6 100644
--- a/src/LogExpert.UI/Controls/LogWindow/StaticLogTabWindowData.cs
+++ b/src/LogExpert.UI/Extensions/LogWindow/StaticLogTabWindowData.cs
@@ -1,6 +1,6 @@
 using LogExpert.Core.Interface;
 
-namespace LogExpert.UI.Dialogs.LogTabWindow;
+namespace LogExpert.UI.Extensions.LogWindow;
 
 public class StaticLogTabWindowData
 {
diff --git a/src/LogExpert.UI/Interface/ILogPaintContextUI.cs b/src/LogExpert.UI/Interface/ILogPaintContextUI.cs
index 39557972..e4465748 100644
--- a/src/LogExpert.UI/Interface/ILogPaintContextUI.cs
+++ b/src/LogExpert.UI/Interface/ILogPaintContextUI.cs
@@ -1,4 +1,4 @@
-using LogExpert.Core.Classes.Highlight;
+using LogExpert.Core.Classes.Highlight;
 using LogExpert.Core.Entities;
 using LogExpert.Core.Interface;
 
@@ -7,7 +7,7 @@ namespace LogExpert.UI.Interface;
 /// <summary>
 /// Declares methods that are needed for drawing log lines. Used by PaintHelper.
 /// </summary>
-public interface ILogPaintContextUI : ILogPaintContext
+internal interface ILogPaintContextUI : ILogPaintContext
 {
     #region Properties
 
diff --git a/src/LogExpert/Classes/LogExpertProxy.cs b/src/LogExpert/Classes/LogExpertProxy.cs
index bf122209..d85448fb 100644
--- a/src/LogExpert/Classes/LogExpertProxy.cs
+++ b/src/LogExpert/Classes/LogExpertProxy.cs
@@ -1,13 +1,11 @@
-using LogExpert.Config;
+using System.Windows.Forms;
+
+using LogExpert.Config;
 using LogExpert.Core.Interface;
-using LogExpert.UI.Controls.LogWindow;
+using LogExpert.UI.Extensions.LogWindow;
 
 using NLog;
 
-using System;
-using System.Collections.Generic;
-using System.Windows.Forms;
-
 namespace LogExpert.Classes;
 
 internal class LogExpertProxy : ILogExpertProxy
diff --git a/src/LogExpert/Program.cs b/src/LogExpert/Program.cs
index 95fa7dfe..0bd88b9b 100644
--- a/src/LogExpert/Program.cs
+++ b/src/LogExpert/Program.cs
@@ -1,26 +1,26 @@
-using LogExpert.Classes;
+using System.Diagnostics;
+using System.IO.Pipes;
+using System.Reflection;
+using System.Security;
+using System.Security.Principal;
+using System.Text;
+using System.Windows.Forms;
+
+using LogExpert.Classes;
 using LogExpert.Classes.CommandLine;
 using LogExpert.Config;
 using LogExpert.Core.Classes.IPC;
 using LogExpert.Core.Config;
 using LogExpert.Core.Interface;
 using LogExpert.Dialogs;
-using LogExpert.UI.Controls.LogWindow;
 using LogExpert.UI.Dialogs;
+using LogExpert.UI.Extensions.LogWindow;
 
 using Newtonsoft.Json;
 using Newtonsoft.Json.Linq;
 
 using NLog;
 
-using System.Diagnostics;
-using System.IO.Pipes;
-using System.Reflection;
-using System.Security;
-using System.Security.Principal;
-using System.Text;
-using System.Windows.Forms;
-
 namespace LogExpert;
 
 internal static class Program
@@ -126,6 +126,7 @@ private static void Main(string[] args)
                         MessageBox.Show($"Cannot open connection to first instance ({errMsg})", "LogExpert");
                     }
 
+                    //TODO: Remove this from here? Why is it called from the Main project and not from the main window?
                     if (settings.Preferences.AllowOnlyOneInstance && settings.Preferences.ShowErrorMessageAllowOnlyOneInstances)
                     {
                         AllowOnlyOneInstanceErrorDialog a = new();