I have a couple of repositories that if I scroll to the end of what is loaded initially in history the screen will lock up and say that it is loading 100 commits, but it will never finish. So I can only get back so far in the history of the repositories. I have tried uninstalling SourceTree and deleting all data in AppData for Atlassian/Sourcetree, and then re-installing Sourcetree, but so far I haven't had any success in this.