Before the registry cleaning, I updated the software drivers for the ATI Radeon HD 4200 display controller. The update did not seem to resolve the "crash on exit" problem.

I installed Mastercam X7 HLE on an old Toshiba Windows 7 Home Premium laptap. Mastercam did not like the Celeron processor and refused to install. I installed Mastercam X7 HLE on a more recent Acer Netbook with WIndows 7 Home Premium, and the install seemed to work fine. I was able to open Mastercam and exit without error. Unfortunately, the Acer Netbook is really a small form factor mini-laptop and it is hard to see things on the undersized screen. This suggests to me that the "crash on exit" problem (at least in my case) is likely caused by leftover junk in the registry from an earlier installation and removal of Mastercam X6 HLE. The next step is to try an aggressive registry cleaning.

I'll see if I can find a Pro system and give it a try. Maybe I will try another Windows 7 Home system, too. FYI. The "Products" page says the OS requirement is "Windows 7 64-bit".

I have this problem consistently with Mastercam HLE X7 on a Windows 7 Home Premium system, Service Pack 1, 64-bit. HLE means "no support". I deleted an expired Mastercan HLE X6 license and then ran the install program for X7. In other words, I did not do any kind of an "update" procedure. If anyone has solved this, or at least narrowed down the possible causes, many of us would like to know.