We were using Xibo before with it hosted on your cloud while we we’re trying it out and we liked it, so we hosted it ourselves. We were able to remotely reboot our players before hand but now we can’t.
The only error I’ve been able to find is XMR not responding.
Could you tell us what exact CMS and player versions are you using please?
Screenshot of the player status window would be helpful as well.
Assuming that you have XMR configured and working, it might be just the case of doing the following:
Displays page -> Edit display -> Advanced tab -> Reconfigure XMR
(Wait for the player to re-connect to the CMS according to collection interval / restart the player)
Check if the commands will work
You can also check that with request screenshot, as with working xmr it should arrive pretty much instantly (ie request screenshot refresh displays page and it should be there already).