This evening I ran into this error while installing Ubuntu 21.04.
I upgraded from 20.04 by formatting the existing ext4 partition.
My BIOS is set to Legacy mode.
Then suddenly I got this error and that ended the installation.
I tried again, but same error message.
Then I read about the efi
I got the error message when I tried to install the Adobe Flash Player package
through Software Center.
However, I could still continue to install the plug-in and it finished without
a problem. After a restart of Firefox the Flash-plugin worked without a
problem.
However, it would be nice
Based on comment #5 I tried installing gnome-desktop, but it was not
there (anymore). In Synaptic I found a package called gnome-desktop-
environment instead, so now I am installing that one.
--
Package gnome is uninstallable due to conflicting dependencies on epiphany
and swfdec-mozilla
