I just upgraded two of my machines from 18.04 LTS to 19.04. The intermediary upgrade to 18.10 went fine, but the upgrade from 18.10 to 19.04 had some issues. It seems like a lot of people are having the same problems -- warnings of errors, that the system may have been made nonfunctional, something about install-info, ... Then I rebooted, and it was working, but how would I know what might be wrong under the hood? A google search took me here: https://bugs.launchpad.net/ubuntu/+source/ubuntu-release-upgrader/+bug/1825425 This guy claims to have a fix... https://bugs.launchpad.net/ubuntu/+source/ubuntu-release-upgrader/+bug/1825425/comments/11 ...so I ran his recommended code, starting with this test: sudo grep -E "WARNING.*pixbuf" /var/log/dist-upgrade/apt-term.log That did return output, so I ran the rest of it: sudo apt install libgdk-pixbuf2.0-dev sudo mv /var/lib/dpkg/info/install-info.postinst /var/lib/dpkg/info/install-info.postinst.bad sudo apt-get install --reinstall install-info for X in $(sudo less /var/log/dist-upgrade/apt-term.log | egrep "Setting up|WARNING.*pixbuf" | grep -B1 pixbuf | grep Setting | awk '{print $3}'); do echo REINSTALLING: $X; sudo sudo apt-get --reinstall install $X; done That seemed to be doing a lot. I hope I needed it! So then I rebooted and it's still working. I get some "System program problem detected" popups, so I tried this to fix it by doing this: sudo rm /var/crash/*.crash Good idea? I don't know! The upgrade also changed Alt+Tab functionality to Super+Tab, which seemed odd because I'd been using Alt+Tab forever. So I went to Settings > Devices > Keyboard Navigation section Switch applications ...and changed it to Alt+Tab Anyway, it is strange, I think, that Ubuntu threw so many errors. I'm not sure how badly that upgrade went, and I don't know if the "fixes" fixed it. I do know that it seems to be working fine right now. Any ideas or suggestions appreciated! Thanks. Best, Mike