Server replied - bad request

Uninstalled, re-installed, same issue ongoing.

Not sure what or why?
Anyone any ideas?

Thanks in advance,

Please have a look at the server logs to get more details about this case. THX

Thanks for getting back.
Through the desktop app, I had a look at the server activity and it seemed to be going fine, until about four days ago. Since then nothing has synced. THere is no error message either, apart from the screenshot I posted earlier.
There is nothing in either 'Sync Protocol' or 'Not Synced'.

I'm talking about the log file of the server WITHIN the server. Like accessing the server via ssh ...
... or you get in touch with the admin/hoster of your owncloud instance .....