I am also using the NVIDIA binary driver. I did the upgrade in a terminal with do-release-upgrade that worked.
The bug is not in update-manager but in the Gtk3 frontend of the command do-release-upgrade from the source package ubuntu-release-upgrader (update-manager internally invokes do-release-upgrade).
Try this command:
/usr/bin/pkexec /usr/bin/do-release-upgrade --frontend=DistUpgradeViewGtk3
It fails as described above.
I am also using the NVIDIA binary driver. I did the upgrade in a terminal with do-release-upgrade that worked.
The bug is not in update-manager but in the Gtk3 frontend of the command do-release-upgrade from the source package ubuntu- release- upgrader (update-manager internally invokes do-release- upgrade) .
Try this command: do-release- upgrade --frontend= DistUpgradeView Gtk3
/usr/bin/pkexec /usr/bin/
It fails as described above.