I had the nightly builds x2go server installed on Centos7, today’s update it left it non-functional.  I’ve installed the stable version but the stable version has the wrong version of xrandr and so will not set your screen dimensions.

     A temporary work around until a working nightly builds is released again is to open a terminal and type xrandr -s (width)x(height), for example my screen is 1920×1080 so I type xrandr -s 1920×1080 (return) and then I’m good.