connection stuck on "initializing display parameters" after rotating display on Ubuntu?

Hi dear community,
I am constantly connecting from my Win10 laptop, with TeamViewer 13.0.6447, to remote Ubuntu 16.04, with TeamViewer 12.something.

Starting tonight, all my attempts to connect are getting stuck, after connection is established and authenticated, at the "initializing display parameters" stage.
It hangs for ~30 seconds and then the connection ends with the usual "please comment about the connection" popup.

The only change I can think of, is that one of the displays on the remote Ubuntu system, was rotated today by 90 degrees to portrait mode.

Could this be the reason?
Any ideas how to solve this remotely?
I am connecting with a password, and I have tried retyping it several times.

Any ideas?
It is weekend now, so no one at the office for a couple of days, and my only solution currently is to drive there and reset the display (if that's the probelm indeed)

thanks!