Table of Contents
- What Happens When Excel Blocks External Links? This Frustrating Update Could Break Your Workflow
- What’s Changing in Excel?
- Timeline of Changes
- What You’ll See
- Why Microsoft Made This Change
- Files That Will Be Blocked
- How to Keep Your Work Running
- Method 1: Registry Edit
- Method 2: Group Policy
- What You Should Do Now
What Happens When Excel Blocks External Links? This Frustrating Update Could Break Your Workflow
Microsoft is making big changes to Excel. These changes will protect you from bad files. But they might also stop some of your work from running smoothly.
What’s Changing in Excel?
Starting in October 2025, Excel will block links to risky files. This means when you try to connect to certain file types, Excel will say no. You’ll see a #BLOCKED error message instead.
Microsoft is rolling this out slowly. It will take until July 2026 to reach everyone. The company wants to keep you safe from hackers who use these links to spread harmful software.
Timeline of Changes
Here’s what will happen:
- Build 2509: You’ll see warning messages when you open files with risky links
- Build 2510: Excel will fully block these links unless you change settings
- October 2025: New policy starts rolling out worldwide
- July 2026: All users will have the new security rules
What You’ll See
When Excel blocks a file link, you might notice:
- A #BLOCKED error in your spreadsheet cells
- Links that won’t update with new information
- Warning bars telling you about blocked content
- Old data that stays frozen in place
Why Microsoft Made This Change
Bad actors have been using Excel links to trick people. They create links that look safe but actually download viruses or steal your information. Microsoft wants to stop this from happening.
The company has been working on security for years. In 2024, they already blocked some dangerous file types in Outlook. They also turned off risky ActiveX controls. This Excel change is part of that bigger safety plan.
Files That Will Be Blocked
Excel will block any file type that’s already on the Trust Center’s danger list. This includes many old or risky formats that hackers like to use. The exact list depends on your Excel settings, but it covers files that could harm your computer.
How to Keep Your Work Running
If you need these blocked links for your job, you have options. Microsoft gives you two ways to turn the blocking off:
Method 1: Registry Edit
- Open the Registry Editor
- Find this path: HKCU\Software\Microsoft\Office\<version>\Excel\Security\FileBlock\FileBlockExternalLinks
- Change the value to 0
Method 2: Group Policy
Your IT team can turn off the “File Block includes external link files” setting.
What You Should Do Now
Don’t wait until October 2025. Start preparing today:
- Check your Excel files for external links
- Test which ones might get blocked
- Tell your team about the coming changes
- Work with IT to decide if you need to override the new rules
Microsoft strongly suggests keeping the new security turned on. Only turn it off if you really need those blocked links for important work.
This change shows how Microsoft is getting serious about security. They’re willing to break some old features to keep users safe. It’s part of a trend where convenience takes second place to protection.
Your Excel files will be safer after this update. But some workflows that depend on external links might need changes. Plan ahead so you’re not surprised when the blocking starts.
The new policy will make Excel less open to attack. That’s good news for everyone who uses spreadsheets for important work. Just make sure you’re ready for the change before it arrives.