It's not a problem of the of the Xserver. A (software) screenshot shows a correct screen, this is what the Xserver "thinks" he would display whereas the real screen is scrambled. But only in the case of a x2go-connection, not in local operations. And - as described before - only when using hardware of somehow low performance together with HDMI connection. I found a posting describing a similar problem: http://lists.x2go.org/pipermail/x2go-user/2016-February/003717.html

Reinhold

On Mon, Oct 2, 2017 at 4:49 PM, K. Reinhold Trier > <R.Trier@it-jobst.de> wrote: >> Hello, >> >> we are using x2go server and clients both on Ubuntu 16.04. After >> configuring new clients on small single board boxes like a ZODAC >> Zbox or a Raspberry Pi 3 we observe severe screen redrawing >> problems an a very poor

Am 02.10.2017 um 17:29 schrieb Ulrich Sibiller: performance in video transfer. E.G. >> shifting a Thunderbird-window over a Firefox-window the latter >> remains scrambled with rests of Thunderbird. We didn't run into >> that problem in our former installation based on Ubuntu 12.04. >> After searching for solutions in the compression method and the >> CPU-performance of the clients I occasionally found out that the >> problem disappears after connecting the client's monitor via VGA >> instead of a HDMI connection. The problem even disappears when a >> HDI/VGA-Adapter is used and the signal is fed to the monitor via an >> VGA-input. This was tested with different monitors. In our former >> clients we only used VGA connected monitors and so we could not see >> the problems. The optical quality of a HDMI connected Monitor is >> notably better than that of VGA connected one, furthermore the VGA >> connection seems to become obsolete, so we would like to stay with >> HDMI. What can be the reason and is there a way change the >> HDMI-output in to a suitable configuration? > > To me this sounds like a buggy Xserver on the client. There's really > nothing in X2go (or better: in NX) that cares about the type of > connection. >

Uli