Corrupted Excel files on iOS High Sierra: How to check and recover?

Hi there,

Excel files on macOS High Sierra can sometimes become slow to open or even appear corrupted, especially if they were created on another platform, have large amounts of data, or were improperly saved.

I would suggest following the below guide to get this issue resolved.

Check the File for Corruption

Try opening in a different app:

Open the file in LibreOffice Calc (free) or Google Sheets.

Sometimes these apps can bypass minor corruption that Excel struggles with.

Use Excel’s Open and Repair feature:

Open Excel.

Go to File → Open → Select the file.

Instead of clicking “Open,” click the dropdown arrow → Open and Repair.

Choose Repair first; if that fails, try Extract Data.

Check File Size and Contents

Large files (>100 MB) or files with many embedded objects, macros, or formulas can slow down loading.

If possible, try opening the file on a more recent Mac or Excel version—Excel 2019/365 handles large files better.

Try Temporary File Recovery

Excel sometimes creates a temporary auto-recovery file:

Look in ~/Library/Containers/com.microsoft.Excel/Data/Library/Preferences/AutoRecovery/

Open any .xlsx files there—they may contain your latest unsaved work.

Export or Save As a New File

If the file opens slowly but isn’t completely corrupted:

Open it in Excel.

File → Save As → New Name / New Location

This can sometimes strip corruption and allow faster loading.

Feel free to reply if these steps don’t resolve your issue

@Marcus_PK has provided some excellent suggestions.

If files are being corrupted, then you need to figure out why & how they are becoming corrupted.

If your Mac is only capable of running macOS High Sierra, then that says your Mac is very old so it is very likely its Hard Drive could be failing & corrupting your files. Bad memory can also do that. My bet is your old Mac has a failing Hard Drive which can cause severe performance issues. You can check the health of the Hard Drive by running DriveDx (free trial period) and posting the complete text report here using the "Additional Text" icon which looks like a piece of paper on the forum editing toolbar.

It is also possible you have an issue with some third party installed software which is affecting system performance. Anti-virus apps, cleaning/optimizer apps, and third party security software can all cause system instability & performance issues. If you are using such apps, then uninstall them by following the developers' instructions. You can run the third party app EtreCheck and post the complete report here so we can review it for possible clues.

If you used a USB stick to transfer the files between devices, then that USB stick could have corrupted the data. Most USB sticks are very unreliable....especially the cheap no name ones & lesser brands, but even some more respectable name brands have bad USB sticks.

I've even had issues sharing files through online cloud services at times.....including myself when I create & upload a file, then immediately download it to the same computer & try to open it.....sometimes it won't work.