The file format and extension dont match | Microsoft Excel | FIX TUTORIAL

This Microsoft Excel notification appears when opening a Microsoft Excel file. Selecting Yes at the notification resumes launching the Microsoft Excel file but does not fix the issue.
Registry Path: HKEY_CURRENT_USER\SOFTWARE\Microsoft\Office\15.0\Excel\Security
Open the Run window, by pressing the Windows key + R
Type regedit, then select OK
In the Registry Editor window, go to the Registry Path mentioned above
Right-click in the blank section on the right, then select New
Select DWORD (32bit) Value
Name the new entry: ExtensionHardening
Set the Hexadecimal value to 0
Voila. Your files should now launch without this error
To use in Command Prompt batch file:
(Copy the text below and paste into notepad, save the notepad .txt file as .bat)
REG ADD "HKEY_CURRENT_USER\SOFTWARE\Microsoft\Office\15.0\Excel\Security" /v "ExtensionHardening" /t REG_DWORD /d 0
Please leave a comment if you were unable to resolve your issue using this method.

[@aleksesmotsar1519]

Perfect solution! Couldn't open *.xls files in Excel without redundant warning and now I can! Thanx.

[@techodsg]

Happy to assist bra, take care👍

[@1AAAjan1]

Thanks a loooot friend, those extensions were headache, may God reward you what's best for you good man 🙂

[@techodsg]

You very welcome. I know how irritating this issue was for me, so glad i could help. take care.

[@aahilrazamurshid8363]

Thankyou for helping

[@techodsg]

Pleasure, this was so irritating lol, had to find a fix

[@AbhishekSingh23980]

I have converted xlsx to csv but when i try to open that file i am facing the same issue. I tried this way also but not working. Can you pls provide more solutions?

[@techodsg]

Ok, have you tried restarting the pc after the change?

[@AbhishekSingh23980]

@@techodsg no. Let me try and will let you know. Thanks

[@MuhammadImran-gt5ie]

Problem not fixed

[@techodsg]

Please provide more detail regarding your issue