I you have an erased type provider that generates a call to a method of an F# type, then try to get the expression from a checked project which uses this, there is an error "A call to '...' could not be resolved.
This is thrown by Microsoft.FSharp.Compiler.SourceCodeServices.FSharpExprConvert.ConvExprPrim. It seems that coming from the TP, the call is represented as a Tast.Expr.Op(TOp.ILCall ...) but the type containing the method has F# metadata, so it will not represented by a TILObjModelRepr case when imported.
I have a minimal test project at https://github.com/Jand42/FCS-TP-error
Failing using FSharp.Compiler.Service 1.4.2.1 and FSharp.TypeProviders.StarterPack 1.1.3.76