I have this strange problem that sometimes occurs and sometimes doesn’t occur. I looked at other similar threads but am not sure where to start to troubleshoot it on our installation. We are running RT 4.0.6 on CentOS release 6.9 (Final). Any advice on how to go about troubleshooting or fixing this? Also how would we upgrade from RT 4.0.6 to the latest version. Any how to guides or problems we might run into? Any help is much appreciated.