ownCloud doesn't synchronise "Server Unavailable"


We are about 15 persons sharing the Cloud and all of us are sharing this problem since a few days already as well.
Our Cloud does not synchronize. We all get the same error message "server replied: Service Unavailable" and "Operation abgebrochen" (=ENG discontinued/ aborted).

Our Webmaster is on vacation abroad and does not seem to have this problem for some reason.

We're using Version 8.2.9 (Upgrade planned for Jan 2018, not possible now).

I'm grateful for any help, as I am no IT pro and the pro we have is not around... Thanks!

Hi there,

Can you enter the server address in your browser and see if you can reach the server?

Try to log in then.

Cloud works normal in Browser, but even w/ logging in again the problem remains in local folder view/ desktop app.
Any further ideas/ suggestions to try?

Thanks for helping!