I deleted all currencies, except EURO.
I think this was wrong, because now I am seeing this error message:
Attention, could not find currency code in the table for id = 191
How can I fix this please?
Use phpMyAdmin & look at table xxx__virtuemart_currencies - you could recreate an entry for 191 (in my VM2.0.16b that entry is for the Croatian kuna). Or rebuild the whole table, you can abstract the original currencies SQL file from the install_required_data.sql which you will find on your server in joomla_root/administrator/components/com_virtuemart/install/
Thanks a lot mate. I added one entry with this ID.
You should never delete the currencies, only unpublish them!