Netbackup Appliance 5020

Hi 

We have netbackup puredisk appliances 5020 connected to media server HPUX 11.31, 7.6.0.3.

Now I am not able to log in tp webGUI of this applainces, getting following error message:

"; nested exception is: javax.net.ssl.SSLException: vrts.vss.sdk.at.exception.VRTSAtException:"

Please suggest.