Collation is not valid for character set
If you get an error like this when saving data (e.g. creating a new user):
COLLATION 'utf8_bin' is not valid for CHARACTER SET 'utf8mb4'
It means you need to fix the collation on your database tables (MySQL/MariaDB). The easiest way is with the
mysql_collation.php CLI script:
For example to change all tables back to
utf8_bin to match this requirement:
php admin/cli/mysql_collation.php --collation=utf8_bin
Note if you are trying to move to
utf8mb4 you need to adjust your database server collation settings accordingly.