older excel file types issue

Question

Hello,

Please check the below error

you are attempting to save a file type excel97-2003 workbooks that has been blocked

Answer 1

Hello @Portal Admin

Welcome to Q&A forum!

In this case, you’re getting this Excel error message:

“You are attempting to save a file type Excel 97–2003 Workbook that has been blocked.” 

This is a security‑by‑design restriction in Microsoft 365. Excel is blocking the old .xls (Excel 97–2003) format because it’s considered less secure and more vulnerable to malware.

To fix this issue, try changing the File Block settings to disable the restriction imposed on certain file types as follows:

Change File Block Settings (if you have permission)

• Open "Excel"
• Go to "File" -> "Options"
• Select "Trust Center"
• Click "Trust Center Settings"
• Open "File Block Settings"
• Uncheck "Excel 97–2003 ...." (Open and Save)
• Uncheck “Do not save”
• Restart Excel

For your information:

• Checked -> Excel blocks opening and/or saving .xls (Excel 97–2003) files
• Unchecked -> Excel allows opening and saving .xls files

If the checkbox is grayed out, it’s controlled by IT policy.

Our first response may not fully resolve the issue, but with your input and detailed answers to follow-up questions, we can work together to find the root cause and a solution.

Thank you for your understanding and cooperation.

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