Nodes in ADMIN_WAIT_STATE & LEAVING after reboot

Hi

I am having a  little knwlodege on vcs , after a reboot of a server i found that node states as ADMIN_WAIT_STATE and other node state as LEAVING this is a 2-NODE CLUSTER

Is this occured due to incorrect configuration file? correct me if iam wrong

please explain me in which situations we find these errors

in which situations we find STALE file/error in MAIN.CF file

Thanks and Regards