Is something wrong with the x2goserver-4.0.1.18-1.el7.x86_64 package in EPEL. The CentOS7 hosts that worked with the previous version (w/MATE desktop) now just open a black window on the client that closes almost instantly. On one system I upgraded only the x2goserver package to make sure it wasn't some other update causing the problem.
-- Les Mikesell lesmikesell@gmail.com