"Excel cannot open the file 'filename.xlsx' because the file format or extension is not valid."

[Jambo123]

Hi

I have a file that is saved on One Drive.

I had a power cut yesterday evening and when I turned on my PC today, the file will not open.

I get the following message:

"Excel cannot open the file 'filename.xlsx' because the file format or extension is not valid. Verify that the file has not been corrupted and that the file extension matches the format of the file"

The file format has not changed so it isn't that.

I've tried repairing on opening but I get the same message.

Is my file really lost forever? This had 5 years worth of work on it and I thought it would always be recoverable if stored on One Drive.

Thanks

[#2]

I managed to fix this.

Version history wasn't showing up on my PC, I had to go to the one drive app and find version history there and recover a previous verison.

[#3]

My issue resolution was because my OneDrive attributes were set to Read-only on some files. Clearing this checkbox fixed this error message.
OneDrive folder > right click > Properties > General > clear Read-only checkbox

[#4]

Download the file from Drive. Now try Open and Repair option to fix the problem.

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