Here's a workaround: I restarted X, then killed gnome-screensaver. At this point I could start gnome-screensaver-preferences, and so switched from 'Random' screensaver to 'Blank Screen'. From this point, ctrl-alt-l started the screensaver, and it worked on all three monitors, and went to the unlock dialog properly on activity. Looking through the various screensaver options, it appears a handful of the screensavers work (apparently the non-3D ones?)
I did see the following error messages when the screensaver activated, but haven't seen any other misbehavior otherwise: (/usr/lib/gnome-screensaver/gnome-screensaver-gl-helper:9778): Gdk- CRITICAL **: gdk_x11_visual_get_xvisual: assertion `visual != NULL' failed (/usr/lib/gnome-screensaver/gnome-screensaver-gl-helper:9779): Gdk- CRITICAL **: gdk_x11_visual_get_xvisual: assertion `visual != NULL' failed (/usr/lib/gnome-screensaver/gnome-screensaver-gl-helper:9780): Gdk- CRITICAL **: gdk_x11_visual_get_xvisual: assertion `visual != NULL' failed A few thoughts on fixes for this bug... 1. Add a new Random2D screensaver theme which activates only the non-3D screensavers. 2. Or add a mechanism to detect if the user's X config can actually run the 3D screensavers and only enable them if the prerequisites are met. 3. Since gnome-screensaver-preferences was crashing, I couldn't turn off the screensaver that was causing the problem. Perhaps include a checkbox for being able to see previews of the screensaver, that's off initially by default or something. -- Lock Screen blanks screen instead of showing screensaver (on external monitor) https://launchpad.net/bugs/71030 -- ubuntu-bugs mailing list [email protected] https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
