once when I was using Sourcetree v2.1.11, every time I start there is comfirn dialog pop up said some dictionary file is invalid and should delete or not, and I chose not for then.
today I update my Sourcetree to version 2.3.1 and the app just can not start up.
somehow I found a solution: uninstall the version 2.3.1 and reinstall v2.1.11 and start it up, the dictionary file thing dialog shows up again and I chose YES to delete that file and then install the version 2.3.1 and it starts up normally.
I'm sorry for not providing the exact content of the confirm dialog since it won't show up any more, I just remember it's a .dic file related to office/16.0/ blablabla.
And SORRY for my poor English.
Sourcetree is a great app, thank you team.