Fix This Error?

[Gor]

So whenever i run an application such as a checker and etc i keep getting this error; http://prntscr.com/3yu3u4
I have already tried repairing my .net framework and can't seem to find a fix.

Help?

 

[Roku]

Do you have .NET 4.5 installed?
Are you running Windows 7 or Windows 8?