This bug has been reported over and over again since it was introduced in 12.04 (just do a LP search for "Maximum number of clients reached"). Now, for some reason in 15.10 it's much easier to reproduce. I hit the problem every day now, whereas I used to be able to go a couple weeks without hitting it. There are many clues in the older reports:
https://bugs.launchpad.net/ubuntu/+source/gnome-screensaver/+bug/263211 seems to have gotten the most attention, and was closed with changes to gnome-screensaver, but I don't think that actually fixed the problem (just made gnome-screensaver quit making the problem show up). It seems to be some kind of X resource leak. I don't know if this is relevant or helpful, but taking some of the comments from that bug report, here are some of the things folks did in that bug to troubleshoot: xwininfo -root -children | wc -l Over time, the resulting number keeps going up. It's currently at 430, and if I open a window (gcalc, for example), I'll get the "Maximum number of clients reached" error when trying to run xwininfo. If I look at the out put of xwininfo -root -children right before that, I see that about 80% of the windows have no name. Also, if I run xrestop, I get a whole bunch of "<unknown>" resources with no associated PID (218 of them at the moment). The other 38 are actual windows I have open. ** Changed in: xorg (Ubuntu) Status: Invalid => Confirmed -- You received this bug notification because you are a member of Ubuntu-X, which is subscribed to xorg in Ubuntu. https://bugs.launchpad.net/bugs/1518411 Title: "Maximum number of clients reached", new in Ubuntu 15.10 To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/xorg/+bug/1518411/+subscriptions _______________________________________________ Mailing list: https://launchpad.net/~ubuntu-x-swat Post to : ubuntu-x-swat@lists.launchpad.net Unsubscribe : https://launchpad.net/~ubuntu-x-swat More help : https://help.launchpad.net/ListHelp
