The issue is generally seen because of some issues with DCOM settings in Cisco Unity or the TAPI service provider (TSP).
Complete these steps on the workstation from where you are trying to play the voice mail.
If this does not resolve the issue, upgrade the Cisco Unity TSP to the latest version that is compatible with Cisco Unity.
Note: Open Unity Tools , click Reporting Tools and double-click Gather Unity System info (GUSI) to check the TSP version.
Refer to the Compatibility Matrix to check for the compatible TSP version. Refer to the Software Download page to download the latest TSP.