General error: 1273 Unknown collation '#32855' in table 'oc_calendarobjects' definition


I am running owncloud with mysql 5.5.55.
It seems like a database table of the calendar plugin now has gone corrupt: I get the following error in ownclouds log
"SQLSTATE[HY000]: General error: 1273 Unknown collation '#32855' in table 'oc_calendarobjects'"
Using mysql commandline I am also unable to access this table... a select statement and even "SHOW TABLESTATUS" returns the same error message.

I was not able to find out what collation #32855 should be anyway. I tried the advice on to convert the collation (by doing a dump or issuing a convert command) but that didn't work either.

Probably this happened while importing an *.ics file using ownclouds web frontend...don't know.
Is there any rescue you could think of without restoring the database? Unfortunately my last backup is two months old because it has been failing silently since then.

Thanks in advance for your help