So the problem is probably still not resolved in the update. The installation script wants to create symbolic links to a location where unfortunately there are already physical files on the disk. So, I deleted the FHD icons:
Code: Alles auswählen
rm -f /usr/share/enigma2/MetrixHD/FHD/*.png
I entered the MyMetrixLite configuration again, confirmed with the green button twice all the changes made (both for saving and applying changes) and the error is now resolved.
Just not sure whether it is necessary to delete all .png recursively also in sub-directories or only in the main directory.