Could not load file or assembly … The parameter is incorrect

Looks like a corrupted assembly being referenced.

Clear both:

1. the \bin folder of your project
2. the temp folder (should be C:\Users\your_username\AppData\Local\Temp\Temporary ASP.NET Files in windows 7)

and see if the error still happens

Depending on if your are running X64 you might need to clean up a couple more spots. Just cleaning up my user directory was not enough.

1. %TEMP%\Temporary ASP.NET Files
2. C:\Windows\Microsoft.NET\Framework\v2.0.50727\Temporary ASP.NET Files
3. C:\Windows\Microsoft.NET\Framework\v4.0.30319\Temporary ASP.NET Files
4. C:\Windows\Microsoft.NET\Framework64\v2.0.50727\Temporary ASP.NET Files
5. C:\Windows\Microsoft.NET\Framework64\v4.0.30319\Temporary ASP.NET Files

This list will grow as if you have other versions of the framework installed.