Joined: 07 Mar 2007
|Posted: Mon May 02, 2016 12:31 pm Post subject: [Solved]Black screen after Plasma 5 upgrade; Failsafe login
|I probably ought to add this to the troubleshooting section in the plasma 5 migration wiki entry, but I don't have time to learn wiki editing.
After following the wiki instructions very carefully on my Gentoo stable KDE 4 system, kde-plasma/plasma-desktop-5.5.5 installed successfully without blockers. SDDM logon started OK, giving the logon progress screen, but then everything went black.
After exploring a number of blind alleyways, I set up a failsafe login mode in SDDM. (Why doesn't it ship with one?) The login modes are in /usr/share/xsessions. I created a "failsafe.desktop" based on "/usr/share/xsessions/plasma.desktop", with
That allowed me to log in; this suggested the problem might be the System Settings OpenGL renderer setting for compositing. I installed the systemsettings5 module to change it.
Systems Setting wouldn't run from the application launcher. It turns out I'd edited its menu entry some time back, and therefore there was a systemsettings.desktop entry in .local/share/applications/ which was trying to load the obsolete KDE4 version. So I cleaned out the cruft in that directory, and also everything in .cache. Now I could change the Compositor system settings to Xrender, and login using a normal plasma desktop instead of failsafe mode.
Now I have a working Plasma 5 desktop. I went back and installed kde-plasma/plasma-meta; in retrospect plasma-desktop was missing too many useful items.