I went from Ubuntu Server 25.10 to 26.04 prerelease. 26.04 comes out next month while I’m on vacation, so I just jumped on it early and took the hit now instead of later. I already knew I was going to run into problems, and I did almost right away.
The first thing that broke was internet after boot. I had no connection until I manually ran sudo systemctl restart NetworkManager. After checking logs, it looked like some boot-order mess involving NetworkManager, netplan-configure, nss-user-lookup.target, and winbind. I was not really using winbind for anything useful, so it was just pointless baggage on my system, and after disabling/removing it, the network side started acting normal again.
Then came the Steam and gaming side. I also had old Flatpak Steam leftovers still hanging around, like com.valvesoftware.Steam.Utility.gamescope and com.valvesoftware.Steam.CompatibilityTool.Proton, both throwing end-of-life warnings even though I do not even use Flatpak Steam anymore. Not a fatal issue, but still more leftover junk causing noise.
Wine on 26.04 prerelease has also been a mess so far. It behaved badly, especially when I tried to run Steam through it. It spent way too much time on locale-related nonsense, and some .exe installers that used to work fine just started hanging or acting wrong. I also had to deal with old Wine cleanup, reinstall confusion, and the usual “is this Flatpak Wine, native Wine, or just old broken leftovers?” mess. Lutris and glxinfo were part of that confusion too, because what the system saw and what I expected it to use were not always the same thing.
Then I hit the MangoHud and GOverlay problem, and that one was the most obvious because it straight up wrecked the image in-game. Bright Memory: Infinite started looking completely broken, with blown-out reflections, giant light bloom, and pixelated garbage all over reflective surfaces. Wayland made it even worse. X11 fixed part of it, especially the “light source looks like the sun exploding in my face” issue, but not all of it. In the end, it turned out my old manually installed MangoHud and GOverlay were part of the problem. I removed the old installs, wiped the old configs so nothing stale got reused, then recompiled both on the new system. After that, the game started looking normal again.
I also had to install missing 32-bit libraries along the way, because Linux gaming still loves to remind you that one missing library can be the difference between “works fine” and “why is this broken now?” The ones I ended up installing were: libgtk2.0-0:i386, libpipewire-0.3-0:i386, libxcb-res0:i386, libc6:i386, libstdc++6:i386, libgcc-s1:i386, libgl1:i386, libvulkan1:i386, libx11-6:i386, libxext6:i386, libxrandr2:i386, libxrender1:i386, libxfixes3:i386, libxi6:i386, libxcb1:i386, libxss1:i386, libasound2:i386.
That is one of the reasons Linux gaming still annoys me sometimes. Two people can have what looks like the same distro, same hardware, same desktop, and still get a very different result just because one system has the right libs, the right rebuilds, the right leftovers cleaned out, or the right bits installed by accident. Once it works, it can work great. But getting there can still be stupid.
To be fair, not everything I hit was a real 26.04 fault. The phased cloud-init update message was just Ubuntu doing phased rollout stuff. The broken audiobook-manager.service was just an old user systemd service pointing to a deleted Python virtualenv, so that was cleanup, not really an Ubuntu bug. But the actual 26.04 problems I hit first were definitely network boot issues, Wine acting badly, Steam/runtime leftovers, MangoHud/GOverlay breaking visuals, and missing libraries.
There will probably be more problems I have not hit yet. These were just the first ones.
They shout from the rooftops as we hear them quickly run down a ladder, onto a boat and back to that sodding god forsaken island.
I think I can hear that lost media song playing in the background

Reactions: CaffeineAddict