Ghost upgrade from 4.44.0 to 4.46.0 breaks ghost

Ghost 4.46 introduced changes to newsletters, which may have introduced an incompatibility with MariaDB (Ghost officially supports MySQL.)

I think there are instances where MariaDB handles date differently. For example, returning NULL, whereas MySQL returns a 0. This is just a hunch. I suggest you take a look at the tables, i.e., take a dump of the database first before making any changes, and look for the table newsletters where created_at is NULL. See if changing to ‘0’ or the current date helps.

If you’ve snapshots on your server, it may be easier to roll back that way.

Once you resolve this, make sure you migrate from MariaDB to MySQL.