Some users of Adobe Acrobat Reader 11 may encounter an error when they attempt to open a PDF file from their email client such as Microsoft Outlook. An error may appear that says “There was an error opening this document. Access denied.” There is a simple fix for this error. Just follow these steps.
- From Acrobat Reader, select “Edit” > “Preferences“.
- Select “Security (Enhanced)” on the left pane.
- Uncheck the “Enable Protected Mode at startup” box.
- Select “Yes” to the prompt about being sure about making this change.
- Click “OK“.
You should be good to go! Adobe Reader 11 should now open files just fine.
Note: this is a per user setting. To take care of it for all user there's an option of creating a GPO with the following registry change:
[HKEY_CURRENT_USER\Software\Adobe\Acrobat Reader\10.0\Privileged] "bProtectedMode"=(0 = off; 1 = on)
In the Acrobat Reader version make sure you have the correct version for the path. You would have the bProtectedMode to be 0.