Upgrading Guest Additions when logged-in, from 7.0.20 to 7.1.4 crashes VM

[Wand]

Windows 10 Host, Windows 10 Guest, latest versions both.

Upgrading Guest Additions when logged-in from 7.0.20 to 7.1.4 crashes the VM, either by inserting the CD and manually executing it or by executing it via menu "Devices/Upgrade Guest Additions".

If while waiting in the login screen you execute "Devices/Upgrade Guest Additions", it works fine.

Trying to login and manually uninstall GA 7.0.20 produces the same crash. It displays a black screen for a few seconds and then the VM restarts.

[Wand]

The above behavior happens only the first time you try to uninstall GA. When the VM crashes and restarts, if you try to uninstall it again, it uninstalls normally. Of course not that this is a safe procedure, the crash may corrupt the VM, but since i noticed it, i reported it.

[helmat]

I found for several of my guests that after upgrading from 7.0.20 to 7.1.4, they had both 7.0.20 and 7.1.4 guest additions installed. Apparently the 7.1.4 guest additions upgrade through the host menu didn't clean up previous installs correctly. Both Windows host and guest. I suspect this observation might be related to this reported issue?

I fixed this on 7.1.4 through this procedure, executed on the guest:

• deinstall 7.1.4 GA
• extract VBoxGuestAdditions.iso from the 7.0.20 GA package (7-Zip is your friend)
• mount this ISO on the guest's CD drive and repair GA
• reboot guest
• deinstall GA (this will remove the 7.0.20 GA)
• reboot guest
• install 7.1.4 GA through the host menu

Both reboots are necessary in my experience.