Dear Zurga,
Thanks for the tip. I did remove the only findable Ancestris directory on my iMac and imported and reinstalled Version 13. The updates installed automatically and as far as I can see all is functioning properly.
There is however a strange phenomenon. The pictogram for " Validation of Gedcom compliance" didn't appear initially and also the "Table of Places" was missing.
After "deactivating" both plug-ins the pictograms appeared and the routines are functioning properly.
It looks as a "double activation" in the main routine,
Kind regards
Jan J.W. Baas