Please note that with Mods that change the AssemblyCSSharp.dll file:
My wife experienced issues when trying to un-check everything and then clicking on cancel: The system may hang at a 'blank'/'black' game loading screen - when terminating the process it'll give a 'file' error and in noted case it was AssemblyCSSharp.dll. So apparently this part of the launcher checks the game files - because how else would it know that there was a change to the AssemblyCSSharp.dll file?
She and I let the system sit there in this state for +5 minutes, wondering if it was checking other files or downloading ones it found 'bad'/'changed' but nothing.
So to me - the error handling is buggy, or hasn't been fully implemented yet since the system just 'hangs.' And again it is the game since upon closer inspection of seeing the mouse pointer and 7daystodie.exe when terminating the process.