xfce – Black desktop after system crash in Xubuntu

[![enter image description here][1]][1]in principle I am a very happy Xubuntu user (Ubuntu 22.04.4 LTS)
I installed a program (CryFS) to test encrypted volumes, but somehow the installation led to a system crash/screen freezing. After rebooting I got a black destkop.
Using timeshift I set system back to how it was the day before (and then how it was 2 days before) but the problem persists.
I attach screenshot of what desktop looks like – you can see that panels show. but desktop is black, also using “right click” with mouse does not do anything – normally it would bring up a short menu.
I tried to refresh XFCE, reboot lightdm…change display manger from lightdm to gdm3 which led to me seeing the wallpaper , but then changed back to lightdm; ran safe boot and ran dpkg, check file systems, … not sure what to do next?
any suggestions would be very welcome!!
thanks