Unable to locate the model you have specified: addons_model

Hello! I have recently installed EE 3.1.1 on a server (where I have minimal control over access to the database and such) and the install seemed to go swimmingly until it “return after install” to the admin panel, where I was given this instead:

Error Unable to locate the model you have specified: addons_model

I haven’t really specified anything yet. I haven’t installed any other modules, everything is out of the box and the server requirements are met in spades. It’s not my first EE install either, though it’s been a little while (since 2.9 or so).

Am I missing something obvious? 😊

Thank you!