IL2CPP error in assembly System.Data.Linq.dll... key... not present in the dictionary

I'm trying to build a game as iOS on Mac for the first time and receiving this error:

Code (CSharp):

1. IL2CPP error for type 'System.Data.Linq.Table`1' in assembly '/Users/larcah/Desktop/r/UsefulPoetry/Cyborg/PrismaticMaze/Temp/StagingArea/Data/Managed/System.Data.Linq.dll'
2. Additional information: The given key 'System.Collections.Generic.IEnumerator`1<!0> System.Collections.Generic.IEnumerable`1<TEntity>::GetEnumerator()' was not present in the dictionary.

It looks like it's having trouble converting a .NET 4.5 library to c++. I'm not sure what to do to work around this or even if it's a by-design limitation that I need to redesign some of my code to avoid dependencies...

I am using my own c# libraries, some of which depend on those core windows libraries. I think those libraries are implemented on Mac as part of Mono but honestly I'm not totally sure about that.

Anyone encounter this, know how to fix/get-past it or able to provide some additional context into the error?

PS: I get the same error trying to build the same project as iOS in Unity on a windows machine. I was able to build a new hello-world project on iOS, was able to build it in xcode & deploy it to test iPhone successfully. Unity 2019.3.0f1.

 

Sorry, I should have been more specific - these are libraries built against .NET Framework using .NET 4.5.
Also, I am able to build and run the same game project as a PC or Mac game without error.

 

Thanks for the help - working on isolating the cause of the error. Will update w/ more info or log bug once it's narrowed down.

 

Ok, narrowed the repro down to be super simple:

Code (CSharp):

1. DataContext context = new DataContext("test");
2. context.GetTable<TestScript>().AsEnumerable();

Only caveat is you need to make the unity project refer to System.Data.Linq.dll via csc.rsp file b/c Unity doesn't reference this by default.

Build that in Unity 2019.03.0f1 (haven't tested other versions) to iOS w/ .net 4.x and it'll throw error:

Code (CSharp):

1. IL2CPP error for type 'System.Data.Linq.Table`1' in assembly 'C:\r\UsefulPoetry.Experimental\Repros\TestProject3\Temp\StagingArea\Data\Managed\System.Data.Linq.dll'
2. Additional information: The given key was not present in the dictionary.

Repro project attached. I will work on logging this as a bug.

PS: noticed the reference to 'TestScript' in the second line of the repro above... don't think the class used there matters, just used the name of the class that code was in.

PPS: link to bug: http://fogbugz.unity3d.com/default.asp?1210714_qs56kv1cjbmevcof

 

Please find the attached file for steps. Replace dll with the one you need. It wirked for us in 2019.3.0f1.

Found solution from following links:
1. https://docs.microsoft.com/en-us/visualstudio/cross-platform/unity-scripting-upgrade?view=vs-2019
2. https://docs.unity3d.com/Manual/dot...201.141767978.1585033012-381588061.1578391050