VirtualBox 6.1.13 (testbuild) tiggers BLUE SCREEN on Windows when UAC Required

[drankinatty]

Host: Archlinux with Linux 5.8.5 VirtualBox: 6.1.13 testbuild (build=139989, sdkbuild=139990) Guest: Windows 7 32-bit (run headless, accessed via rdesktop) Guest Additions: version=6.1.13-139990

Blue Screen is triggered each time User Account Control Activated to allow changes to windows.

This problem seems to be triggered by Windows 7 User Account Control (UAC). I can't even install simple updates to PuTTY, etc. without 6.1 causing a BLUE screen and reboot. This is triggered any time you are prompted to allow a change to your computer with UAC. The UAC dialog is displayed and the remainder of the screen is darkened. After choosing "Yes" to allow the change, the darken background is not removed from any open windows and about 5 seconds later BLUE SCREEN, and the Virtualbox 6.1 reboot screen is shown.

This will occur if you simply attempt to start the command prompt with "Run As Administrator". I have 3 Minidumps collected if needed and the Event Viewer reports the critical error as "Kernel Power" (which doesn't look very useful)

As a test, I disabled UAC completely and attempted the updates to PuTTY again. With UAC disable, there is no problem. I can update software as normal without the Blue Screen on 6.1. So the bug in 6.1 causing the BLUE SCREEN crash is triggered any time elevated privileges are needed and UAC is activated.

I have run this same VM for 5+ years and never had any problem with the 5.1 or 5.2 Virtualbox branches. There is something new in 6.1 that triggers a crash when Windows UAC is activated.

Let me know if the Minidumps will be of any use or if there is other documentation I can provide and I'm happy to attach them.