"The form required to view this message cannot be displayed" error accessing Organizational Forms Library in Outlook 2003

I had a VB6 program running on a server using Outlook 2003 client to create appointments. The appointments used a custom Outlook form stored in the Organizational Forms Library. Suddenly the program started spitting out this error:

"The form required to view this message cannot be display. Contact your administrator."

If I used the Outlook Client (on the server) to try to design the form via Tools-Forms-Design Form-Organizational Forms Library-{shift}+Open then I got the following error message:

"The form you selected cannot be displayed. The form required to view this message cannot be display. Contact your administrator."

The solution was to clear the Outlook Forms cache. This can be done via:

1. Click on the "Tools" menu


2. Click on "Options"


3. Click on the "Other" tab


4. Click the "Advanced Options" button


5. Click the "Custom Forms" button


6. Click the "Manage Forms" button


7. Click the "Clear Cache" button


8. Close and OK through all Outlook Property/Option windows

Credit for these steps from http://www.experts-exchange.com/Software/Server_Software/Email_Servers/Exchange/Q_24342937.html