I'm not having this problem at all. Since you mention Task Manager, I'll assume you are using some version of Windows.
The first suggestion that pops to mind is to check where your database *.rmgc file is stored. Some users make the mistake of putting their database inside the C:\Program Files folder. That no longer works in Win7 and above. Relocate all of your database files to somewhere permitted by Windows - some users prefer a subfolder under MyDocuments; other users prefer a subfolder directly in the C: drive root folder; and, still other users prefer to use a subfolder on a separate hard drive (this is my preference).
My next thought is that you may be using a virtual drive or a cloud drive. If these are unavailable to RM, it could cause RM to lock up and stop responding.
If none of these fit your case, then please provide more detail about the problem: what exactly are you doing when the lock up occurs?
[edited 5:50 pm]
Whoops!! TomH is correct - I initially referred to *.rmgb above, and it should have read *.rmgc - FIXED !!