Sometimes saving brings up an error.

[micheus]

ptoing, I'm seeing your image now. (it was blocked before) :/

That dialog should be shown if you try to the hotkey for save command. If you use the File menu option, does it also appears?
Can you attach your preferences.txt? (that can help me to test the hotkey issue)

About the crash I'm not sure I can reproduce without use the same scene that yours.