A classic source of run problems in C# can be if your using components that are 32bit in an application with the Platform. Setting the Platform Target to x86 will often solve this whilst still allowing the app to run on an x64 platform.
Menu > Project > Project Properties > Build > Platform Target
Feel free to comment if you can add help to this page or point out issues and solutions you have found. I do not provide support on this site, if you need help with a problem head over to stack overflow.