Sometimes an Ubuntu in-place upgrade will error, failing to install packages like:
systemd-sysv init gvfs
At the end of the install, the Ubuntu upgrade installer said the install had failed, and it was going to revert with
dpkg --configure -a.
That will typically also fail.
As a last resort, consider a recovery procedure as below.
This will keep the new Ubuntu version if it works.
Open a second Terminal, WITHOUT clicking close on that dialog:
apt install gvfs init systemd-sysv
In the same new Terminal: