Adobe Reader DC must disable Online SharePoint Access.

Disabling SharePoint disables or removes the user’s ability to add a SharePoint account access controls the application's ability to detect that a file came from a SharePoint server, and disables the check-out prompt.

Verify the following registry configuration: If configured to an approved DoD SharePoint Server, this is NA. Note: The Key Name "cSharePoint" is not created by default in the Adobe Reader DC install and must be created. Utilizing the Registry Editor, navigate to the following: HKEY_LOCAL_MACHINE\Software\Policies\Adobe\Acrobat Reader\DC\FeatureLockDown\cSharePoint Value Name: bDisableSharePointFeatures Type: REG_DWORD Value: 1 If the value for bDisableSharePointFeatures is not set to “1” and Type configured to REG_DWORD or does not exist, then this is a finding.

Configure the following registry value: Note: The Key Name "cSharePoint" is not created by default in the Adobe Reader DC install and must be created. Registry Hive: HKEY_LOCAL_MACHINE Registry Path: \Software\Policies\Adobe\Acrobat Reader\DC\FeatureLockDown\cSharePoint Value Name: bDisableSharePointFeatures Type: REG_DWORD Value: 1