When you try to open an Excel or Word file and see the message "The file format or file extension is not valid," it is natural to worry that your work data might be lost.

I think many people have encountered this error when submitting Excel files, Word documents, or reports.

Microsoft is working to resolve a known issue that prevents some users from opening Excel email attachments in the new Outlook client. According to a service alert (EX1189359) seen by BleepingComputer ...

Converting spreadsheets to PDFs is possible in just a few easy steps By doing this, you can ensure your data looks the same on every device You can also protect your work from unwanted edits or ...

Have you ever sent an Excel file to a colleague, only to realize they couldn’t open it because of compatibility issues? Or perhaps you’ve spent hours perfecting a spreadsheet, only to see its ...

Microsoft has announced that it will start disabling external workbook links to blocked file types by default between October 2025 and July 2026. After the rollout ...

Excel workbooks containing massive datasets and complex formulas can become incredibly slow, even on powerful computers. Lagging scrolling, slow formula recalculation, and lengthy save times are ...

Every time I try to load a file, I get an error message saying: "Invalid Excel format." I've verified that the Excel file is not corrupted and is in .xlsx format, but the program still throws the same ...

Abdullah is a certified Google IT Support Professional. The “File Format is Not Supported” error on WhatsApp can appear when you’re trying to send a video ...