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Troubleshooting Viewmail for Outlook (VMO) Issues

Cisco Employee


How to isolate problems with VMO when intermittent exceptions are thrown, Outlook crashes, hangs, or when any other abnormal behavior occurs.

Feature Information

Unity or Unity Connection with VMO versions 8.5 and higher

Troubleshooting Methodology

The #1 cause of VMO related issues is due to the fact that it rides on top of a 3rd party API called Addin Express.  This API is most often what causes conflicts with other installed Outlook add-ins and plug-ins within customer environments, which may even use a form or different flavor of Addin Express as well.

You always want to make sure to turn on VMO tracing using the Enable Diagnostics checkbox in the VMO settings.  Then collecting all of the  below information will help lead you and or TAC to problem isolation:

Are you running in an 100% compatible setup as explaind in the Compatibility Matrix?

     UC -

     Unity -

What version of VMO?

How many users are affected?

Have you tried on a different workstation to see if behavior persists?

Has this ever worked, and if so on which VMO version(s)?

Are there any 3rd party add-ins/plug-ins installed in Outlook on affected machines?

Have you disabled ALL add-ins/plug-ins except for VMO and see if the issue persists (problem isolation - which software is conflicting)?

Have you disabled VMO to confirm that the behavior only happens when its installed (problem isolation - is VMO even the culprit)?

Have you installed a "vanilla" Operating System with no corporate image/software/policies, etc., a default Outlook profile, and then VMO?

Data Analysis

It's very crucial that you understand there can be a lot of false negatives and false positives with testing in these scenarios because of the flaky and intermittent nature of various symptoms.  As a result, make sure you test and re-test so don't be in a hurry to trust that it's resolved!  Also, re-verify you're running a supported config per the compatibility matrix.  It's important to narrow down add-ins/plug-ins seem to be causing the conflict, as well as having corresponding VMO logs so that information can be gleaned.

Common Problems

Most common problems are Addin Express conflicts with other add-ins/plug-ins installed.  Major offenders seen by TAC thus far have been document management plug-ins (eDocs, etc.) and some Adobe PDF plug-ins.


Q:  Is there a quick or easier way to determine why VMO may be causing abnormal Outlook behavior?

A:  No.  It's a very manual process to narrow down the issue and it's the only way to determine which add-ins/plug-ins are causing the problem.  Once we know which ones are problematic, we can then determine if there are any fixes Cisco can implement in the code, or if customers need to contact their 3rd party plug-in/add-in vendor for assistance.  From a TAC perspective, many times it takes the vendor to determine why their plugin is crashing or acting odd.  This way, if Cisco is unknowingly doing something incorrect, it can be addressed.

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