2.9 Course Backup DDL Error

I have a clean 2.9+ site with a single course on it.  Thought it would be a good idea to back the course up, so I chose the backup option in Course Administration and went through the option screens, but at the crunch point, the process fails with:

This is clearly a permissions/access issue, but I'm logged in as an administrator, the username is the root MySQL user and the site plus course are running fine without similar problems elsewhere, so what's different that would be causing the backup to fail?

thanks