I'm back with a continued tale of determination and woe.
I had all sorts of issues trying to upgrade from 1.9 -> 2.2 which were solved (or so I thought) by going 1.9 -> 2.1 -> 2.2. When I tried this it worked first time on a copy of our site.
A couple of weeks later we arranged to take the site offline for a day to update the site for real. All went well, or so we thought.
It turns out everything appeared to be working except when you try to review any quiz attempt. You get the following error.
Coding error detected, it must be fixed by a programmer: Invalid context id specified context::instance_by_id()
So I rolled back and continued testing. It seems that I can upgrade to 2.1 without any problems. No errors during upgrade, everything works fine. However, when I upgrade to 2.2 I get this same error on all quiz attempts.
1.9.19 -> (2.0.10 ->) 2.1.9 -> 2.2.6 ... -> 2.3.3 (ideally).
(I've tried it with and without 2.0 and it seems to make no difference.)
-> 2.1 all fine
2.1 -> 2.2 error.
Please help, I'm starting to dream about Moodle upgrades...