Microsoft Excel is making a major change around blocked file types - here's what we know

Microsoft Excel.

• Microsoft Excel will now disable blocked file types from workbook links by default
• The files will either fail to refresh or show a #BLOCKED error
• Other safety updates are coming to Excel soon, so be sure to update

External workbook links which point to file types blocked by Excel's Trust Center will be disabled by default starting in October 2025, as Microsoft tightens down on reducing the potential security risks associated with indirect access to unsupported or high-risk file types in its spreadsheet software.