This browser is no longer supported.
Upgrade to Microsoft Edge to take advantage of the latest features, security updates, and technical support.
![](data:image/svg+xml, %3Csvg xmlns='http://www.w3.org/2000/svg' height='64' class='font-weight-bold' style='font: 600 30.11764705882353px "SegoeUI", Arial' width='64'%3E%3Ccircle fill='hsl(128, 8%, 22%)' cx='32' cy='32' r='32' /%3E%3Ctext x='50%25' y='55%25' dominant-baseline='middle' text-anchor='middle' fill='%23FFF' %3EA%3C/text%3E%3C/svg%3E)
Hi,
I'm hoping someone can help me with 2 xlsx files that have been corrupted.
I use iCloud to store my documents, I finished working on the 2 files in question on my MacBook in the morning and then later in the day successfully viewed them (not modified) on my iPhone using the Office 365 app.
When I came to open the files again, they are unable to be opened on any device using either numbers or excel. I have tried on my iPhone, MacBook and a Windows 11 PC. The error message is:
"Excel cannot open the file 'ABCDEF.xlsx' because the file format or file extension is not valid. Verify that the file has not been corrupted and that the file extension matches the format of the file."
I have tried changing the file extension to xls. I've tried to open and repair the files using Excel on Windows however that hasn't worked either. I've used a couple of trial versions of recovery software and the preview shows the first sheet is there but the remaining sheets aren't which are vital to the spreadsheet.
Does anyone have any ideas or experience of this issue? I've noticed the timestamp of last saved has changed to the date and time I opened them on my phone. I'm not sure why Office365 resaved these files without me making changes or asking me.
Thanks
A family of Microsoft spreadsheet software with tools for analyzing, charting, and communicating data.
Locked Question. This question was migrated from the Microsoft Support Community. You can vote on whether it's helpful, but you can't add comments or replies or follow the question.
Is there a structural solution available for this from Microsoft?
Unfortunately none of the suggestion in this thread work for me.
Pretty pathetic issue to have which renders 365 useless on iCloud.
This answer has been deleted due to a violation of our Code of Conduct. The answer was manually reported or identified through automated detection before action was taken. Please refer to our Code of Conduct for more information.
Comments have been turned off. Learn more
After experiencing multiple instances of this issue with Excel on iOS and Mac OS in iCloud, I moved my spreadsheets to OneDrive and am now able to edit on iOS, MacOS and Windows flawlessly. I will keep iCloud for MacOS-related activities, but exclusively use my personal OneDrive account for file synchronization between multiple OS's. Maybe someday I'll be able to revert back to iCloud, but I'm happy to have my options back.
This just happened to me today too. It was working just a few days ago and now it's not? Hopefully someone is listening a will issue a fix soon..Hope it doesn't come down to finger pointing between Microsoft and Apple.
Exact same problems for me. AND this also happens with Microsoft Word. I thought it had something to do with when iCloud syncs the file at the same time as when the file is open. But perhaps it is another issue.