Emma Richardson

Did you clear caches after removing the plugin? Did you actually uninstall it from the web interface (so that it would remove all database entries?)

And after uninstalling that plugin, does debugging show anything else?

Have you tried an enrollment with full debugging on to see if there are any messages? Does it happen on every course or just a single course? When did it start? What happened before it started? I suspect you have some plugin that is incompatible or causing issues...what plugins do you have installed?

The interval needed to be contained in the inner brackets apparently.