Developing a COM integration is an iterative process. You write some COM code, test it, make needed changes, and test again. As you continue this process, you may encounter a common problem where it appears that code that worked previously has now stopped functioning. You may be tempted to suspect your code, but the likely problem is a hidden instance of the application you’re integrating with.
When you create a new COM reference to an application, an instance of that application is created invisibly. If your Dexterity-based application terminates abnormally, which is common during COM development, you may leave instances of the other application running. When your code doesn’t seem to be working, it likely is interacting with a hidden instance of the application you’re integrating with.
If you’re having problems with a COM integration, use the Windows Task Manager to list all of the processes currently running. If you see multiple processes for the application you’re integrating with, use the End Process button to terminate them, and then try your integration again. If you continue to have problems, restart both Dexterity and the application you’re integrating with to eliminate any COM communication issues.