Further to my previous post, AC 9 would not let me open any files the other day. Even ones I had been working on previously.
After many lost hours, I was able to open them by the following.
When opening a project, you have the choice under "Set up Work Environment" at the startup window to choose which work environment ot use. Mine would always go to "Last Profiled Used". I found that by always changing this setting on startup to my own created profile, AC would open every time.
Even after you have set the profile to your own profile, each time you start AC it will default to "Last Profile Used". Each time you should change it to your own profile, or one supplied by AC.
There is a bug report to help fix this problem. Check FAQ Article # 699 at tr.graphisoftus.com
Hope this helps.
Grant