Issues when installing vanilla gnome on Ubuntu 21.10
Solution 1:
Ran into the same issue. There seems to be some naming changes that result in this problem. The mailing list did provide an answer:
I have a manual fix for this.
Edit "/var/lib/dpkg/info/vanilla-gnome-default-settings.postinst"
Change "gdm3-theme.gresource" to "gdm-theme.gresource"
Then "sudo apt install -f"
The vanilla gnome setup now works as expected.
https://bugs.launchpad.net/ubuntu/+source/ubuntu-gnome-default-settings/+bug/1935767/comments/3
I can confirm this worked for me!