Issue: Moab is rejecting client requests from non-root users.

Affected Versions: All

Symptom: When running any client commands as a user the request is rejected with the following error:

[user@submithost]$ showstats 
ERROR: server rejected request - could not authenticate client using .moab.key 
ERROR: communication error hpc-master:42559 (remote server rejected request, message 'no signature value specified') 

Solution: Check the following

1. That /tmp is not filled and that the user can write to /tmp

2. Check that mauth has the following permissions and setting
   ls -l /opt/moab/bin/mauth
   -r-s--x--x 1 root root 79506904 Mar 26 11:15 /opt/moab/bin/mauth

1. It is important that mauth has the same owner and group as the moab binary!
2. mauth needs the setuid bit on the owner so that the binary can read the .moab.key which can only be read as root (chmod u+s mauth). 
3. Check that the Moab process was not started as another user.
4. Check that the .moab.key has 400 as its permissions and is on all submit hosts.
5. If you have just implemented the .moab.key you should have stopped Moab before applying the .moab.key. 
6. Make sure $MOABHOMEDIR is in the environment and that it points to the correct path. By default it will be "/opt/moab/".