When you create an appointment for a contact that does not have an e-mail address in Microsoft Dynamics CRM 4.0, you incorrectly receive the following error message:

Important This section, method, or task contains steps that tell you how to modify the registry. However, serious problems might occur if you modify the registry incorrectly. Therefore, make sure that you follow these steps carefully. For added protection, back up the registry before you modify it. Then, you can restore the registry if a problem occurs. For more information about how to back up and restore the registry, click the following article number to view the article in the Microsoft Knowledge Base:

This problem is fixed in the latest cumulative update rollup for Microsoft Dynamics CRM 4.0.
For more information, click the following article number to view the article in the Microsoft Knowledge Base:
To enable this hotfix on the computer that is running Microsoft Dynamics CRM 4.0, follow these steps:

1. Under the
   HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\MSCRM\
   registry subkey on the Microsoft Dynamics CRM server, add the following DWORD registry entry:
   AddNotificationToApptForNoEmailAddress
2. Set the value of the registry entry that you just added to 1.

To enable this hotfix on a computer that is running Microsoft Dynamics CRM for Microsoft Office Outlook, follow these steps:

1. Under the
   HKEY_CURRENT_USER\SOFTWARE\Microsoft\MSCRMClient\
   registry subkey on the Microsoft Dynamics CRM client for Outlook, add the following DWORD registry entry:
   AddNotificationToApptForNoEmailAddress
2. Set the value of the registry entry that you just added to 1.

Note This problem was originally fixed in Update Rollup 10 for Microsoft Dynamics CRM 4.0.
For more information, click the following article number to view the article in the Microsoft Knowledge Base:

Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.

For more information about software update terminology, click the following article number to view the article in the Microsoft Knowledge Base: For more information about Microsoft Business Solutions CRM software hotfix and update package terminology, click the following article number to view the article in the Microsoft Knowledge Base: