It’s been some time that I try to update my system and it fails; every time is some Gnome package, but today I could actually read what the problem is: it seems like Discover is trying to remove a package that’s needed:
Can’t remove org.gnome.Platform/x86_64/45, it is needed for: com.inform7.IDE
I’ve been seeing these two Gnome packages in the update page of Discover for some time, like they couldn’t be updated since their update was requested, and now they are hindering all the process:
It looks like the older Gnome 45 Platform flatpak (org.gnome.Platform/x86_64/45) is EOL, but you have some application (Inform) that is also old(er) and still depends on it.
You might look at running flatpak update which might give some extra information on it, but the only way to cure the problem may be to uninstall the inform flatpak and use their rpm instead.
I am unable to install this software myself via flatpak because the needed Gnome 45 runtime is no longer available.
I don’t know if it is a bug in flatpak or Discover, as I didn’t think either would try to remove on its own any flatpaks that are still needed by an installed application. But I well could be wrong. It was not attempting to do so in the thread I linked to above.