Information
This policy setting allows you turn off the file validation feature. The recommended state for this setting is: Disabled. The file validation feature ensures that Office Binary Documents are checked to see if they conform against the file format schema before they are opened, which may help protect against certain types of attacks.
Solution
To implement the recommended configuration state, set the following Group Policy setting to Disabled. User Configuration\Administrative Templates\Microsoft Excel 2016\Excel Options\Security\Turn Off File Validation Impact: 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.