We are on 10.1.2138.11.  this problem seemed to start when we upgraded to this version.  on some random PCs we can't control the screen but on those same systems we CAN do other remote management (services,command prompt, etc).    doesn't matter which vlan/network, it appears to be totally random.  but seemingly getting worse slowly.     I can disable firewall on system that doesn't work, disable firewall on manageengine server, nothing helps.    any ideas?      

on systems that remote doesn't work I'll  just  see the green connecting screen.  never connects.