Hello... we just recently upgraded to 2.X - we are getting this error on this page: /backend/index.php/customers/index
What should we do? Thanks! Dan @twisted1919
if you take a look in the database, in the mw_customer table, do you see the "parent_id" column?
if you do, then it means most likely the cache didn't flush during the upgrade, so try to clear the cache and see if that helps. https://www.mailwizz.com/kb/clear-cache-command/
If you don't see the column, things aren't okay...