We are also having issues with the 12.1.2512 update. Below is the mini dump. This only seems to be happening on Win 7 machines (All so far are x86). We are able to access the OS through Safe mode and Uninstall Avast! and the computer will resume normal boot operations. We have rolled back with a manual install to 11.2.2511 and the computer continue operate normally. Updated back to 12.1.2512 and computer restarts the BSOD loop.