Recently I faced some strange behaviour with my Xfce 4 (.10) after I had plugged in a beamer. On first login after startup it wouldn't apply the window theme I set, nor would it use my preferred icon theme.
Also, setting the theme again with the xfce settings dialog (xfce4-appearance-settings) would not have any effect. Logging out and logging in again solved the issue temporarily, though.
Usually I already use a dual monitor setup and the beamer just switched place with my desktop monitor. So this was obviously a dual or multi monitor problem, and the first place I looked in for error messages was ~/.xsession-errors. There I encountered a line saying:
"The program 'xfsettingsd' received an X Window System error"So the error occured in xfsettingsd, which also explained why using the settings dialogs hadn't had any effect later on.
Luckily, google would directly lead me to https://bugzilla.redhat.com/show_bug.cgi?id=867455 when searching for this error message, where I found the solution:
By simply deleting
.config/xfce4/xfconf/xfce-perchannel-xml/displays.xmlI was able to fix the error. As mentioned in the bug report, the file was recreated. Nevertheless I recommend to backup the file, since one never knows if such a file contains additional configuration markup you would maybe want to have access to later.
I hope this information can help somebody. If you want to thank me or want me to add something or maybe have any suggestions for improvements, I would be glad if you left me a comment.
Until then, see you soon