Since installing the latest update a couple of weeks ago, my Windows 8.1 VM has become increasingly unstable. I have encountered the following freezes: Upon rebooting, tile screen becomes frozen and unresponsive. When I minimize from full screen to minimized, screen becomes black and stays the same when returning to full screen. It takes a couple of minutes before the VM is usable. When coping files to multiple network shares (seems to be triggered at 3 simultaneous copies), VM freezes up. The only way I can get it to become responsive is to Suspend and then bring out of suspended mode. When randomly navigating to tile screen. Once it is frozen at this point, I have to reboot.