This answer applies to all Runtime Errors.

Unfortunately, RT errors tell us almost nothing of value. Generally they're functionally limited to saying something along the lines of “Word couldn't complete the requested task.” We already know that because Word didn't compete the assigned task. The next step, determining why, is more difficult and the official translation of RT error 6028, for instance, doesn't help, “If you encounter this error message while running an app, the app was shut down because it has an internal memory problem. There are many possible reasons for this error, but often it's caused by an extremely low memory condition, a bug in the program, or by defective hardware drivers.” 

To generate more useful information, we ask customers who'd like to take advantage of our free Service Desk to use the Diagnostic Portal to help investigate, diagnose, and fix the issue or to provide the Service Desk with all the information it will need to accomplish that task.