I believe these problems always occur when you fall too far behind in updating and upgrading computer technology. I'm thinking any number of the 1000's of security patch updates Win 7 has received over the past decade could wreak havoc on Sonar 8.5.
Why are you still running a 32 bit version of Sonar on Windows 7 x64?
I still have a 20 year (?) old,
old, OLD Rain laptop that refuses to die that's loaded with XP and Sonar 8.5 Producer and it still rocks as a solid performing, but extremely limited, almost wimpy DAW compared to Sonar Platinum. A lot of cool, useful, and exciting things have happened to Cakewalk DAW technology since..
Why are you still using the ancient v8.5, which I believe was optimized for Win XP, when you an get a modern day, infinitely more refined, STABLE and powerful version of Cakewalk by Bandlab?
It will cost you NOTHING to upgrade to CbB except for a bit of a learning curve getting used to a newer sleeker Skylight interface.
Or....
The only sure way I know how to keep rock'in on and productive with Sonar 8.5 is to install it on a Windows XP SP 3 machine.