Dynamic keyword requires `System.Runtime.CompilerServices.DynamicAttribute' to be defined

[AIIX]

Using Unity 5.5.0.b7

Error: Assets/GILES/Code/Classes/Serialization/Converters/pb_ObjectContainerConverter.cs(23,43): error CS1980: Dynamic keyword requires `System.Runtime.CompilerServices.DynamicAttribute' to be defined. Are you missing System.Core.dll assembly reference?

[karl-]

Are you compiling with the complete .NET profile and not subset?

[AIIX]

Yes using .Net 2.0 and not the subset. I even reInstalled the final release of Unity 5.5 the error is still the same. Also tried changing the project settings in Visual Studio to .Net 4.0 the error remains.

Additionally I'm using unity3d 64bit on Windows10. Also tried the above in Unity 5.4 beta release on the Linux editor the error is the same.

[tomaszzackiewicz]

The same problem. I tried to add:
using System.Runtime.CompilerServices.DynamicAttribute;

But I get the error:
Assets/GILES/Code/Classes/Serialization/Converters/pb_ObjectContainerConverter.cs(5,39): error CS0234: The type or namespace name DynamicAttribute' does not exist in the namespace System.Runtime.CompilerServices'. Are you missing an assembly reference?

[karl-]

What platform are you targeting?

[tomaszzackiewicz]

Now, PC, 64bit on Windows10, but later I would like to use it on mobile too.

[karl-]

Looking at the code again I think you could safely just comment out then entirety of pb_ObjectContainerConverter.

[tomaszzackiewicz]

I have commented out all the code in the file. No errors and I can run the project, but I'm not sure if it won't prevent me from suing serialisation.

[karl-]

If I recall correctly that path was never actually used - I abandoned it for some reason, or at the least didn't find time to finish it. So you should be able to serialize and deserialize without issue.

[tomaszzackiewicz]

Ok, thank you.

[SavedByZero]

I'm confused, what's the exact solution here? I never had an issue using the dynamic keyword with .net 2.0 or .net 2.0 subset until recent 5.X releases, so why is a basic variable type suddenly breaking Unity and looking for a class from 4.6?

[kevinw]

I'm running into this issue as well, with Unity 5.6.0f3, under both .NET 2.0 and .NET 2.0 Subset.

[SavedByZero]

The only thing that worked for me was replacing dynamic with object, and that's only because I'm a weird case with an xml reader that reads variable types as attributes and puts them into a dictionary. In most cases, I would think dynamic and object are fairly different.