So far, Sublime3 has been fantastic, but I recently had a serious problem.
I had set Sublime3 to be the default editor for working on .js userscripts for Greasemonkey in Firefox. It was working fine for a long time, but then I tried opening a file named 'mininav-1' (by right-clicking on it in the icon menu) and Sublime3 froze on the loading screen.
Subsequently removing the corrupt code failed to fix the session file and any unsaved changes could have been lost.
Anyway, after deleting 'Session.sublime_session' and running the program, it opened and created a new session file.
Luckily, prior to encountering this bug, I had previously edited the User Settings to Save on focus switch, so nothing was lost, but this could potentially effect other people.