Issue with using external DLL build against .NET 4.0

So I’m having trouble with importing a dll build against .NEt 4.0. I’m wondering is it even possible to use something like that in unity?

I’m trying to use this → That needs framework 4.0, when I try to add this dlls into Plugins folder I’m getting internal compiler exception that says:

Internal compiler error. See the console log for more information. output was:
Unhandled Exception: System.TypeLoadException: Could not load type ‘System.Runtime.Versioning.TargetFrameworkAttribute’ from assembly ‘Cudafy.NET’.

Any idea if that dlls are usable within Unity3d? Thank you

It’s .NET 2.0 only I’m afraid.

Also a few bits of that are missing on phones etc.

Actually Unity3D 3.5 has been updated to C# 3.5. If the source code for this library is available you may try to recompile it for 3.5. If it do not use any 4.0 features like parallel for etc - it may help.
Android and iOS devices works with .NET 2.0 only.