IL2CPP error when building for IOS

When building our game for IOS we are getting an error related to IL2CPP. I haven't been able to find a solution in the existing topics.

Unity 5.6.0f3
Scripting backend: IL2CPP
Api Compatibility Level: .NET 2.0 or .NET 2.0 subset (no difference)

I tried changing the scripting backend to Mono2x but then I also get an error that I can't find a solution for (see error below this error).

Any suggestions please?


IL2CPP

Failed running...

IL2CPP error when building for IOS