An unhandled exception occurred: Value cannot be null. Parameter name: self

I’m using Fody for the first time and I’m getting an unhandled exception. It’s a netstandard 1.1 library project. I added both Fody and ReactiveUI.Fody packages and then added the FodyWeavers.xml by hand. The view model has two constructors (one without parameters and another with a parameter). It has two ObservableAsProperty but exceptions still happens when I remove them.

1> Fody: Fody (version 1.29.4.0) Executing 1> Fody/ReactiveUI: ReactiveUI 7.0.0.0 1> Fody/ReactiveUI: ReactiveUI.Fody.Helpers 2.0.65.0 1> Fody/ReactiveUI: ReactiveUI 7.0.0.0 1> Fody/ReactiveUI: ReactiveUI.Fody.Helpers 2.0.65.0 1>MSBUILD : error : Fody: An unhandled exception occurred: 1>MSBUILD : error : Exception: 1>MSBUILD : error : Value cannot be null. 1>MSBUILD : error : Parameter name: self 1>MSBUILD : error : StackTrace: 1>MSBUILD : error : at Mono.Cecil.Rocks.TypeDefinitionRocks.GetConstructors(TypeDefinition self) 1>MSBUILD : error : at ReactiveUI.Fody.ObservableAsPropertyWeaver.Execute() in C:\projects\reactiveui-fody\ReactiveUI.Fody\ObservableAsPropertyWeaver.cs:line 41 1>MSBUILD : error : at ReactiveUI.Fody.ModuleWeaver.Execute() in C:\projects\reactiveui-fody\ReactiveUI.Fody\ModuleWeaver.cs:line 31 1>MSBUILD : error : at lambda_method(Closure , Object ) 1>MSBUILD : error : at InnerWeaver.ExecuteWeavers() in C:\projects\fody\FodyIsolated\InnerWeaver.cs:line 161 1>MSBUILD : error : at InnerWeaver.Execute() in C:\projects\fody\FodyIsolated\InnerWeaver.cs:line 82 1>MSBUILD : error : Source: 1>MSBUILD : error : Mono.Cecil.Rocks 1>MSBUILD : error : TargetSite: 1>MSBUILD : error : System.Collections.Generic.IEnumerable`1[Mono.Cecil.MethodDefinition] GetConstructors(Mono.Cecil.TypeDefinition) 1>MSBUILD : error : 1> Fody: Finished Fody 22ms.

[kswoll]

Thanks for looking into it, @RostislavST, I’ll get to it this weekend.

[kswoll]

Hi, sorry for not getting back to you sooner. I’ll take a look at it this weekend.