Cannot compile .exe with specific .dll. (but with other .dlls created the same way)

Hey guys,

I have a problem in Unity which I cannot resolve on my own. In the "past" (~ 2 weeks ago) I created different libraries for all kinds of Unity games. (e.g. an Input Handler which allows rebinding of keys at runtime) They are all build in form of a .dll which was compiled in VS 2012 with mostly standard build configuration.

For the past few days I have been working on a Network Handler which handles creating of servers, connecting to servers, player synching and so on. I created the scripts in Unity and I also developed them in Unity. I'm just porting the scripts into a new VS 2012 project and then I build the .dll.

All previous .dll's worked just fine but with the new .dll i get the following error when I try to compile the "game" in Unity with the .dll:

Internal compiler error. See the console log for more information. output was: Unhandled Exception: System.TypeLoadException: Could not load type 'System.Reflection.AssemblyConfigurationAttribute' from assembly 'mscorlib, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089'.

at Mono.CSharp.Driver.Compile () [0x00000] in :0

I tried many different things to solve the problem but none of them seem to be working:

• changed the .NET framework from 2.0 up to 4.5 and back

• changed assembly configuration

• recreated the project

• tried to sort out dependencies

• changed used .NET framework in Unity to 2.0 and also back to the 2.0 Subset

• deleted all code in the project, recompiled .dll and imported it into the Unity project

• took the project files from another working .dll and replaced the code with the NetworkHandler

Am I just missing something? By the way: the NetworkHandler scripts are just working fine when i place them inside any Unity folder.

Any help would be appreciated.

Thanks in advance!