Godot caches information and editor settings (layouts, window positions, open files, etc) for your project. Sometimes this can get corrupted after an abnormal termination. I've had to clear this cache once or twice due to the editor being unusable after a crash.
On Linux systems the cache lives here:
/home/[username]/.config/godot/projects
I'm not sure of where it lives on Windows, I think it's either AppData\Local\Godot\projects
or AppData\Roaming\Godot\projects
. And I don't know about OS X.
Just delete or rename that "projects" folder and hopefully that will do the trick.