I spoke with support yesterday and they were able to solve this issue for me.  I had to identify the return type that was impacted (i.e. 1120S, MA S-Corp).  Then close Proseries, go to "Control Panel," choose uninstall programs, doubleclick on ProSeries 2021 and choose the impacted return types (i.e. 1120S, MA S-Corp in my case) and choose "Uninstall" to remove just the impacted programs (This will not cause you to loose any client returns).  Let the uninstall of the impacted return types complete, then re-open ProSeries, click on the "Update" menu and choose "Select and Download New Products."  Choose the return types that were just unistalled (i.e. 1120S, MA S-Corp in my case) and let ProSeries download and install the products.  Once the installation completed, I was able to file the returns normally and the error code no longer appeared.