Howard Miller

I don't know... looking at the code, I can see how the function that generates the parameter for the url_select() call can legitimately return null. However, presumably, it doesn't normally happen or other people would have seen this.

Maybe somebody else has a better idea than me. I would have to do some code level debugging and that requires being able to recreate the fault.

Which Moodle version?

Please increase Debugging to Developer level and get us the full trace of the error.

Can you confirm that the Moodle upgrade process ran after you replaced the database?

What do you mean you 'imported' the database? You needed to completely replace the database and run the upgrade.

What *exactly* is the full error you are seeing?

Looks like this - https://moodle.atlassian.net/browse/MDL-63544