NIEHOST_UNKNOWN: Cannot connect to Message Server

Hello SAP Experts,

The Java server cannot be started as it cannot get connected to the message server.

The log contains following entries:

• ERROR => cannot connect to Message Server.
• LOG => connecting to Message Server.
• ERROR => MsIAttachEx: NiBufConnect to sapxxxxx01/3901 failed (rc=NIEHOST_UNKNOWN)
• LOG => Run level 0 completed.
• LOG => Instance state is "Instance terminated"

Please help me resolve the error.