In my case, I've already CentOS 5.3 running zcs 5.0.18, and I tried to upgrading to zcs 6.0, but i get same problem.
Ok, zcs 5.0.18 has been removed from server, now I've zcs 6.0 already running and can't find some error message from zimbra.log / /opt/zimbra/log/*
in case, i want adding blocked attachments extentions and I get the problem when tried to saving configuration [Global Setting]
Error message:
message: cnt is not defined fileName: [servername]:7071/zimbraAdmin/
js/Admin_all.
js.zgz?v=090830143748 lineNumber: 7838 stack: ()@[servername]:7071/zimbraAdmin/
js/Admin_all.
js.zgz?v=090830143748:7838 ((void 0))@[servername]:7071/zimbraAdmin/
js/Admin_al...
message: cnt is not defined fileName: some file not found?
Please advise........