DTOO110 - Blocking as default file block opening behavior must be enforced.
This policy setting allows you to determine if users can open, view, or edit Word files. If you enable this policy setting, you can set one of these options:- Blocked files are not opened- Blocked files open in Protected View and can not be edited- Blocked files open in Protected View and can be edited. If you disable or do not configure this policy setting, the behavior is the same as the 'Blocked files are not opened' setting. Users will not be able to open blocked files.
Set the policy value for User Configuration -> Administrative Templates -> Microsoft Word 2016 -> Word Options -> Security -> Trust Center -> File Block Settings 'Set default file block behavior' to 'Enabled: Blocked files are not opened'.