I just upgraded Ubuntu from 14 to 16.04, and I really regret it now. Many things now don't work within X2go. I've completely lost KDE, which I see is a known issue, but for some reason now Firefox and many other applications don't work. I even tried gnome-calculator and it doesn't work now, but LibreOffice does. I'm not sure if it's because of the graphical toolset used or not. The most important app not working for us is Eclipse. All of the applications that don't work function fine with an exported X session, but there is just something in X2go that is keeping it from working.
kernel: [12762.555968] firefox[65546]: segfault at 0 ip 00007f9d91f649bf sp 00007ffecd72a238 error 4 in libc-2.23.so[7f9d91ecf000+1bf000] kernel: [12762.572675] crashreporter[65553]: segfault at 0 ip 00007f4bf9c009bf sp 00007ffe73a9d248 error 4 in libc-2.23.so[7f4bf9b6b000+1bf000]
kernel: [12787.466816] [UFW BLOCK] IN=eth0 OUT= MAC=01:00:5e:00:00:01:00:25:00:ef:46:fb:08:00 SRC=128.174.227.254 DST=224.0.0.1 LEN=44 TOS=0x00 PREC=0x00 TTL=1 ID=63656 PROTO=UDP SPT=52742 DPT=8612 LEN=24 kernel: [12800.095585] gnome-calculato[65714]: segfault at 0 ip 00007fcfab8999bf sp 00007ffd744e1ff8 error 4 in libc-2.23.so[7fcfab804000+1bf000]
kernel: [13492.855643] eclipse[68620]: segfault at 0 ip 00007f4bca47c9bf sp 00007ffd8d26b2b8 error 4 in libc-2.23.so[7f4bca3e7000+1bf000]