So I use SourceTree and I love it. However it was crashing on me every time I tried to open a repository!

Additionally, my visual studio just stopped using line numbers as well, and was giving me an error message. So I looked it up.

Ran into this link: http://stackoverflow.com/questions/14897032/visual-studio-2012-line-number-outlining-gutter-missing.

So I went into my AppData/Local/Temp folder and saw there were more than 60 thousand files there! So I just deleted them all. That fixed it :D