XFCE suddenly not applying any themes any more

Hello people out there!

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.xml

I 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

suluke