I have problems with 2 of my nodes after upgrade.

They keep going missing.

I upgraded again and one of them gave this error;

"
setting permissions
Starting Darket damon hold on
DarkNet server starting
Error: An error occurred while setting up the RPC address 0.0.0.0 port 51473 for listening: bind: Address already in use
DarkNet server starting
Starting Masternode
error: couldn't connect to server
Upodate now Done
"

and the other gave this error;

"
setting permissions
Starting Darket damon hold on
DarkNet server starting
error: {"code":-28,"message":"Loading block index..."}
Starting Masternode
Upodate now Done
"

Both of them blocks are not updating.

What should I do?