Artist 6.5 crashing when editing MIDI

The program is crashing when I click on notes in the piano roll editor (old/new projects). I have been using it for about a year and this just started happening today. Tried computer restart - didn’t help.
How can I solve this?
Would it help to uninstall and re-install the program?
If that’s what I have to do I will probably install Cubase Artist 7 which I have the licence for.
I assume all my previous project should open fine in 7?
Would appreciate advice.