22.04 LTS upgrade two days ago from a fully-upgraded and maintained original 18.04.2 install from ISO in 2019.
During upgrade I did receive several warning popups; can't recall the text now because I clicked "report" and the upgrade continued. The warnings were pretty generic.
At any attempt to run any video, or even just start Totem, fails with "Totem could not startup (sic). Some necessary plugins are missing. Make sure that the program is correctly installed."
VLC Media Player doesn't even get that far: simply nothing happens.
This lead down several deep rabbit holes: 1) which plugins are missing? 2) where are they in the file system? 3) what source would provide those plugins; etc etc
Ended up removing and reinstalling Totem. No joy. That led down another rabbit hole where I ended up with
sudo apt install ./totem-plugins_42.0-1ubuntu1_amd64.deb
in an attempt to install missing plugins; still no joy.
Want to post this w/out reading other similar posts because they seem to refer to Totem installs that do work to some degree, or wander off into Window Media Player or something.
How can a plain-jane 22.04 LTS upgrade to a fully-maintained, original Ubuntu 18.04.2 ISO install get b0rked so badly?
sudo apt update
andsudo apt install totem-plugins totem-plugins-extra
sudo apt install totem-plugins
should do it.