Yesterday Sourcetree app turned off by itself and it was gone from my applications, spotlight search, launch pad- everywhere.
I've downloaded latest version from https://www.sourcetreeapp.com/ extracted the archive and placed it under /Applications folder (there was no overwrite warning). After this I've launched it and got source tree window with all bookmarked repositories, yet I'm getting error "k3diff not found" (see image).

Except that, the sourcetree app has wrong logo in the dock (whereas it displays ok in spotlight and when changing windows with cmd+tab).

Is it normal? What caused the app to uninstall (?).