You have 1 tables that do not use your preferred database engine Use the commandline upgrade method to convert them

manual update, first login:

System > Upgrade phplist Database

“You have 1 tables that do not use your preferred database engine
Use the commandline upgrade method to convert them.”

i have no idea

@wolfey
you can check de engine via this mysql command:
SELECT TABLE_NAME, ENGINE FROM information_schema.TABLES WHERE TABLE_SCHEMA = ‘dbname’

For my database they are all ‘InnoDB’.

You can change the engine to InnoDB via:
ALTER TABLE tablename ENGINE = InnoDB;

SiteGround Site Tools > Site > MySQL : “Database names are automatically generated. You can assign a label later.”

4 databases, only 1 phplistdb - why would phplist complain about others (phpbb, etc)?

Probably not.
You really have the check the engine of the tables in the phplistdb.

@wolfey You must have set the variable $mysql_database_engine in the config.php file. If you don’t want to see this warning then just remove that setting from the file.