Problem with XServer - _XSERVTransSocketUNIXAccept: accept() failed

I run a headless Manjaro server with Xhost and Xvfb (for a display) and after about 236 instances of a program running, the server starts lagging a lot and the error _XSERVTransSocketUNIXAccept: accept() failed is printed infinitely on the screen. Does anybody know of a fix for this? I've searched the Internet for solutions, but I've come up empty. I've read in one forum post that it's because of «clients using lots of true-type fonts», but even if it is I have no idea what to do to fix it.