This policy setting allows you to turn off the file validation feature. If you enable this policy setting, file validation will be turned off. If you disable or do not configure this policy setting, file validation will be turned on. Office Binary Documents (97-2003) are checked to see if they conform against the file format schema before they are opened.
Set the policy value for User Configuration -> Administrative Templates -> Microsoft Word 2016 -> Word Options -> Security 'Turn off file validation' to 'Disabled'.
The following resource is also helpful.
This security hardening control applies to the following category of controls within NIST 800-53: System and Communications Protection.This control applies to the following type of system Windows.