Solved:
I renamed the following two directories and it worked! The stripes are gone and I have now the desktop and respective icons back.

Alt+F2 then type xterm and press Run.

mv /home/user/.config/xfce4 /home/user/.config/xfce4.old
mv /home/user/.config/xfce4-session /home/user/.config/xfce4-session.old

Reboot afterwards. The side effect is that you will louse your desktop configuration, but that isn't really so bad.