The possible cause for that problem is that network configuration is interfering with COM/DCOM operations.
Because the Media Master control bar relies on Distributed Component Object Model (DCOM) communication to communicate with the Cisco Unity server, verify that DCOM communication is enabled on the subscriber workstation and on the Cisco Unity server. The Media Master will not work when DCOM communications are blocked.
To resolve this issue, perform these steps:
On the Cisco Unity server, browse to the CommServer\Cscoserv\Ciscopca\WEB-INF directory.
Use a text editor to open the web.xml file.
Find unityurl and verify that the value enclosed in quotation marks is the IP address (not the hostname) for the Cisco Unity server that is hosting the AvXml web service and portal.
Close the web.xml file.
Restart the Tomcat service.
For more information on this issue, refer to Cisco bug ID CSCsb16152.
The latest revision of the Cisco Unity Permissions Wizard has been updated to correct this issue. To obtain the latest version, refer to Cisco Unity Tools.
After the Permission Wizard is re-run, the Enable Distributed COM on this computer(DCOM) checkbox is unchecked. MediaMaster relies upon Microsoft DCOM, so check this box to ensure DCOM is enabled on the Cisco Unity server.