Why does the “Unblock” button not appear in file properties for some users or computers?

Dear @Diego Uriarte,

Thank you for reaching out to the Microsoft Q&A Forum. 

I understand that you're having a specific and unexpected issue regarding the inconsistent appearance of the "Unblock" button in file properties. From your description, that the same file, from the same source, exhibits different behavior on different Windows 10/11 machines is a clear indication that the cause is system configuration or policy, not the file itself. From my research, this behavior is tied to a core Windows security feature called the Mark of the Web (MotW).

The "Unblock" checkbox only appears when a file contains a specific piece of metadata called the Zone.Identifier Alternate Data Stream (ADS). This flag tells Windows and Microsoft Office (Word/Excel) that the file originated from an external, potentially untrusted source (like an email attachment or website download). When the "Unblock" button is absent, this means the file never received the Zone.Identifier ADS or the ADS was removed during the download or saving process.

The most common reasons why the Mark of the Web (and thus the "Unblock" button) is missing on one machine but present on another are:

1.Group Policy (GPO)

Your organization's IT may have a Group Policy enabled on some systems that prevents the application of the Zone.Identifier ADS. The key GPO setting is: User Configuration > Administrative Templates > Windows Components > Attachment Manager > "Do not preserve zone information in file attachments." If this is Enabled, the file will not be marked as coming from the Internet, and the "Unblock" button will not appear (because the file is not considered blocked).

2.Email Client Handling

Different versions or configurations of the email client (e.g., Outlook, webmail) or a company's mail gateway/security software might process and save attachments differently. Some security scanners strip the ADS, treating the file as safe.

3.Trusted Locations

The local Office security settings on the working machine may have the folder location added as a Trusted Location, which overrides the need for a security prompt, effectively clearing the "blocked" status without showing the button.

To ensure the "Unblock" button appears consistently, you must ensure the Zone.Identifier ADS is preserved. To ensure the macro files work consistently, you can use one of two strategies below:

1: Ensure All Files are Flagged (Show the Button)

You would need to ensure the GPO setting above is Disabled or Not Configured across all machines to preserve the zone information.

2: Bypass the Block Entirely (Recommended for Business Templates)

The most robust solution for trusted internal templates (.dotm, .docm) is to configure the Office Trust Center settings to trust the file's source, which completely bypasses the need to manually unblock files.

Add Trusted Location:

• Save the templates to a specific network share or local folder.
• Open Word or Excel > File > Options > Trust Center > Trust Center Settings...
• Go to Trusted Locations.
• Add the shared folder path (using the UNC path, e.g., \fileserver\templates) as a Trusted Location.

Use PowerShell to Unblock (IT Fix):
For files that are currently blocked and are being inconsistent, your IT staff can force the unblock using PowerShell, regardless of whether the button appears: Unblock-File -Path "C:\Path\To\Your\File.docm"
For reference: Unblock-File (Microsoft.PowerShell.Utility) - PowerShell | Microsoft Learn

I hope this information helps clarify the situation and provides you with workable solutions. Should you have any further questions or need additional assistance, please don't hesitate to reach out. We're always here to help. Have a wonderful day! 

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