Information
This policy setting controls how Office handles documents when they fail file validation.
Office File Validation is a feature that performs security checks on files. If Office File Validation detects a problem with a file, the file cannot be opened.
The recommended state for this setting is: Enabled: Open in Protected View
Files that have failed file validation outside of Protected View could allow malicious code to execute on the system or the network.
Solution
To establish the recommended state via configuration profiles, set the following Settings Catalog path to Enabled: Open in Protected View
Microsoft Excel 2016\Excel Options\Security\Trust Center\Protected View\Set document behavior if file validation fails
Impact:
Files that are blocked by the validation fail rule will not open on a user's computer.