I'm running 2.8/4gbs for my server and it's still kicking people off, these are the messages I get: Happens every now and then and the server also gets laggy. My plugins (They're all current, and I've also tried disabling each of the Essentials plugins) I have a feeling it's Orebfuscator but that's mandatory for my server...
Same problem, i have a fix! 20:34:52 [INFO] GroupManager - INFO - Data files refreshed. Thats the problem, disable groupmanager refresh