ownCloud "Downgrading not supported" after apt-get upgrade

Question

I am running an ownCloud installation on Raspbian on an RPi2 and I just ran:

apt-get update
apt-get dist-upgrade

Now I get the following message when I try to go to my ownCloud-site in the browser:

Downgrading is not supported and is likely to cause unpredictable issues (from 8.2.2.2 to 8.1.5.2)

I did not make any changes and definitely didn't do any downgrade (consciously). The files are stored on an external HDD and seem to be unaffected. I wasn't really actively using my cloud storage yet (fortunately), so I wouldn't really mind if the data I had put there was lost, but I'd like to keep the other data stored on the HDD (outside the ownCloud folder) if possible. What would you suggest as the best way forward? I thought about just removing ownCloud via apt-get purge - or would that be unsave or leave some junk on my system (I'd maybe have to delete the database manually)? And how can I avoid this problem in the future?

Answer 1

Try to connect to the official repository

wget -nv https://download.owncloud.org/download/repositories/stable/Ubuntu_14.04/Release.key -O Release.key
apt-key add - < Release.key

sh -c "echo 'deb http://download.owncloud.org/download/repositories/stable/Ubuntu_14.04/ /' >> /etc/apt/sources.list.d/owncloud.list"
apt-get update
apt-get dist-upgrade