Today was once again the 1st friday of the month, and the time of the scheduled monthly confluence.csc.fi maintenance break, starting at 16:00 UTC+2.
The agenda was to patch a recent security bug, and if possible, upgrade from 4.1 to 4.2.
After working on the system for 3 h 30 min, confluence was upgraded from 4.1.10 to 4.2.13, and the security flaw patched. Trouble was, the calendar plugin stopped working.
Since there were only a few page edits done during the maintenance break, I decided to roll back to 4.1.10 from a snapshot. This way, the calendar will still work for the projects using it. Any edits made during the maintenance break were lost and will have to be done again, sorry for the inconvenience.
The maintenance was finished by applying the security patch to 4.1.10.
We will study the calendar plugin more. Unless we find a solution how to port it to 4.2.13 or higher, internal calendars will have to be phased out. Google calendars should still work. The other costly alternative is team calendars (for 10000 users).