Corosync Died , How to fix it ?

Well what do the logs say? heck, you even put it in bold. How many nodes in the cluster? How long have you had the cluster running? is this the first time you have tried to rejoin the cluster with this node? how did the node leave the cluster?

AKA, provide more info so we can help!
 
I have 4 nodes connected, actually this node is part of them, so in total there are 5 nodes.
but suddenly this one is separated from the cluster. So i want to re-join this node. but I got that following error.

p.s i don't know how can this node leave the cluster...