fatalorg.apache.axis2.AxisFault: security

A client is accessing our JBoss server. In the past, we set up a keystore and everything worked fine.

That certificat expired and we've installed the new one. Now the client is getting the following error -

HTTP/1.1 500 Internal Server Error
Date: Mon, 14 Apr 2014 13:25:44 GMT
Server: Apache/2.2.22 (Win32) mod_jk/1.2.27 mod_ssl/2.2.22 OpenSSL/0.9.8t
X-Powered-By: Servlet 2.5; JBoss-5.0/JBossWeb-2.1
SOAPAction: ""
Accept: text/xml
Connection: close
Transfer-Encoding: chunked
Content-Type: text/xml;charset=UTF-8

This shows up in the log -

Sender PartyName: eReinsure.com, Inc
Sender PartyId: urn:duns:125137211
Receiver PartyName: StoneRiver
Receiver PartyId: urn:duns:026334564
MsgId: B625F9FC-DEA9-85D5-C764-86E880CAC4B4
Error Message: fatalorg.apache.axis2.AxisFault: security

What's going on with this? How can I find out more?