I am on windows and since about a month I use version 1.2.

Since about a week every time I close the last open file I get the message "Inkscape encountered an internal error and will close now".
It is not a big problem, at that moment everything is saved, so I don't lose anything, but I wonder what causes this.

I´d try to reset Inkscape´s Preferences and check again.

OK, thank you, that helped!

I get this error when I try to run latest 1.3 version..

Inkscape encountered an internal error and will close now.

Edit: I ran it as administrator and it opened successfully.