Outlook 2007 may stop responding when you select an e-mail message that is restricted by Information Rights Management

To resolve this issue apply hotfix 960535.

For more information, click the following article number to view the article in the Microsoft Knowledge Base:

960535 Description of the Outlook 2007 hotfix package (Mso.msp, Outlook.msp): December 16, 2008

After you apply this hotfix you must set the DisableDrmErrorCachingWithOM registry entry.

To have us fix this problem for you, go to the “Fix it for me” section. If you would rather fix this problem yourself, go to the “Let me fix it myself” section.

To fix this problem automatically, click the Fix this problem link. Then click Run in the File Download dialog box, and follow the steps in this wizard.

Note This wizard may be in English only; however, the automatic fix also works for other language versions of Windows.

Note If you are not on the computer that has the problem, you can save the automatic fix to a flash drive or to a CD, and then you can run it on the computer that has the problem.

Now go to the "Did this fix the problem?" section.

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:

322756 How to back up and restore the registry in Windows

To resolve this issue, follow these steps to set the DisableDrmErrorCachingWithOM registry entry:

1. Click Start, and then click
   Run.
2. Type regedit, and then click
   OK.
3. Locate and then click the following registry subkey:
   HKEY_CURRENT_USER\Software\Microsoft\Office\12.0\Outlook\Options
   
4. On the Edit menu, point to
   New, and then click DWORD Value.
5. Type
   DisableDrmErrorCachingWithOM, and then press ENTER.
   
6. Right-click
   DisableDrmErrorCachingWithOM, and then click
   Modify.
7. In the Value data box, type 1, and then click OK.
8. Exit Registry Editor.

Now go to the "Did this fix the problem?" section.

Check whether the problem is fixed. If the problem is fixed, you are finished with this article. If the problem is not fixed, you can contact support.