I have been having a rather serious problem after updting to KDE 4.10: if I make any customization to my desktop, when I login into my account I get a black screen with only my mouse active. Alt - F2 works, and I can launch apps from there, but still no desktop. The problem has been reported (for 4.10) for other distros. The option to delete all plasma config files from .kde4 only works until changes are made to the desktop.
updated the KDE in 12.3 to 4.10?
You know the default KDE on install in 12.3 is 4.10 and there shouldn’t be any need to do an update to this (other than incremental updates from the OSS-Update repo).
Same problem here on 12.3 but not after specifically updating to kde 4.10 because as farcusnz is saying this is the default kde. It just happened after accepting the update proposal of apper (did not check what was in it, maybe upgrade to 4.10.3?) and suddenly I got black a screen with some error information on it. For 30s you could move the mousecursor and then it freezes. Reboot, tried the update again => same issue. Strange, today apper did not offer the update anymore. Maybe people are working on it? This problem might be related to this maybe ?: https://forums.opensuse.org/english/get-technical-help-here/applications/486676-kde-4-10-3-update-broken-kdebase4-session-package-3.html
No. That is a completely different problem, which caused kdm not to start, i.e. you would land in text mode right after boot.
Also this bug was only present for a short while in the additional KDE repos. If you don’t use them, you can’t have that problem.
As to the original problem:
Never seen that either.
Are you using NVIDIA graphics cards maybe? Then try to add your user to the “video” group.