When you check in a file to SharePoint using Office 2010 that is encrypted with password protection, you may receive the following error:

 

 

Cannot perform this operation. The file is no longer checked out or has been deleted.

By default, when you encrypt a file using password protection, the file properties, or metadata, are also encrypted. When the file properties are encrypted, SharePoint cannot read the existing properties, and therefore cannot write new property values to the document in SharePoint.

To fix this error, try the following steps to disable metadata encryption:

  1. Open the Registry Editor by going Start > Run and typing regedit, or run it from the Command Prompt by going to Start > Programs > Accessories > Command Prompt
  2. Navigate to HKEY_CURRENT_USER\Software\Microsoft\Office\14.0\Common\Security
  3. If you get to Common and the Security key does not exist, create it by right-clicking on Common and selecting New > Key and name it Security
  4. Inside the Security key, create a new DWORD value by right-clicking and selecting New > DWORD (32-bit) value and name it OpenXMLEncryptProperty
  5. Right-click OpenXMLEncryptProperty, select Modify, and in Value Data, enter the number 0, and click OK.
  6. Close all Office applications and then test to see if the issue is resolved