So, ical4android expects uid2445 on API level 17+, but in your case, you have Android 4.2.2, but the column isn’t there. You can try to reset your calendar storage (Settings / Apps / Calendar Storage / Delete data) and add the DAVdroid account again. If it still doesn’t work, I’d suggest to use another firmware which behaves as documented (either a firmware update from your manufacturer, if available, or a custom ROM like CyanogenMod).
Does not seem to sync 'Organisation'
I sync Android with Owncloud and have found that the 'Organization Field is not syncd in either direction.
Is this possible to correct?
I installed on a second device and it worked with Organisation on that - so I uninstalled from the first device and when I re-installed it worked there too.