Strong name validation failed exception .NET assembly

I am trying to modify an assembly(say someApp.exe) through code injection tools/libraries. I have a reference dll( say reference.dll) which is called inside someApp.exe after code injection.

When I try to launch someApp.exe , I get visual studio debugger saying "Could not load file or assembly 'someApp, Version=1.0.0.0, Culture=neutral, PublicKeyToken=98ec9cb7b15b7e98' or one of its dependencies. Strong name validation failed. (Exception from HRESULT: 0x8013141A)

What is could be going wrong and what is the fix?