Fix Excel Recovery Mode: "Excel was able to open the file by repairing or removing the unreadable content"

TL;DR

Excel opened your file but showed a repair dialog — the .xlsx / .xls file has internal corruption. Work through these fixes from least to most destructive:

• Use File → Open → Open and Repair manually — you get more control over what gets removed.
• Copy all sheet data into a fresh workbook.
• If Excel already auto-repaired and you clicked OK, check the repair log it showed before you accepted — it lists exactly what got dropped.

What Actually Happened

When Excel shows:

Excel was able to open the file by repairing or removing the unreadable content

...the ZIP-based XML structure inside your .xlsx has one or more broken parts. Here's what typically causes it:

• File got truncated during a network save — SharePoint and mapped drives are the usual suspects.
• Two people had the same file open and one save partially overwrote the other.
• Anti-virus or backup software locked the file while Excel was still writing.
• The disk hit 0 bytes free mid-save. This happens more often than you'd think on shared drives.
• An old .xls file from Excel 97–2003 with a damaged FAT structure.

Excel's auto-repair is silent. It drops whatever it can't parse — no warning, no undo. Depending on the damage, you can lose charts, pivot tables, conditional formatting rules, or entire sheets.

Step 1 — Read the Repair Log Before Clicking OK

Excel shows a collapsible repair summary before you get access to the file. Don't click OK yet. Click "Click here to see what content was removed" — it opens an XML log file listing everything that got axed. Save that log somewhere. You'll want it when your boss asks why the Q3 pivot table is gone.

Step 2 — Open and Repair Manually

Close the auto-repaired file without saving. Now do it yourself, with more control:

• Open Excel with no file loaded.
• Go to File → Open → Browse and navigate to the file.
• Click the dropdown arrow next to the Open button. Choose "Open and Repair".
• Try "Repair" first — it preserves formulas and formatting. Only pick "Extract Data" if Repair fails. Extract Data strips everything down to raw values.

Step 3 — Copy the File to a Local Path First

Network paths cause more false corruption reports than actual file damage. Before assuming data loss, copy the file locally and try again:

# Windows — copy from network share to local temp
copy "\\\\server\\share\\report.xlsx" "C:\\Temp\\report_local.xlsx"

# macOS
cp "/Volumes/NAS/report.xlsx" "~/Desktop/report_local.xlsx"

If the local copy opens without a repair dialog, the original problem was the network path — not corruption. Save the file back under a new name.

Step 4 — Inspect the XLSX Internals

An .xlsx file is just a ZIP archive with XML inside. You can crack it open and find exactly which part is broken:

# Windows (PowerShell)
Rename-Item report.xlsx report.zip
Expand-Archive report.zip -DestinationPath .\report_unzipped

# macOS / Linux
cp report.xlsx report.zip
unzip report.zip -d report_unzipped

Focus on these four files first — they cover 90% of corruption cases:

xl/workbook.xml       # Workbook structure
xl/worksheets/        # One XML file per sheet
xl/sharedStrings.xml  # All text cell values
xl/styles.xml         # Cell formatting rules

Open them in VS Code. Truncated content or encoding errors near the end of the file are a dead giveaway. Small damage? Fix the XML by hand and re-zip:

# Re-zip after manual fix (Linux/macOS)
cd report_unzipped
zip -r ../report_fixed.xlsx .

Rename to .xlsx and test in Excel.

Step 5 — Restore a Previous Version

Sometimes the fastest fix is going back in time. Check these sources:

• OneDrive: right-click the file in OneDrive web → Version History → restore a version from before the corruption timestamp. OneDrive keeps up to 500 versions for Microsoft 365 subscribers.
• Windows File History: right-click the file in Explorer → "Restore previous versions".
• SharePoint: open the document library → select the file → Version History → restore.

Step 6 — Extract Raw Data With Python

If the file is too damaged for Excel's own repair, openpyxl is worth trying. It's more lenient with malformed XML than Excel is:

pip install openpyxl

import openpyxl

wb = openpyxl.load_workbook('report.xlsx', data_only=True, read_only=True)
for sheet_name in wb.sheetnames:
    ws = wb[sheet_name]
    print(f"--- Sheet: {sheet_name} ---")
    for row in ws.iter_rows(values_only=True):
        print(row)

You won't get formulas or formatting. But the raw numbers and text are often recoverable even when Excel gives up.

Stop This From Happening Again

• Save locally, copy back. When working on a network share, save to C:\Temp\ first, then copy the finished file back. This alone eliminates the majority of network-related corruption.
• Set AutoRecover to 5 minutes: File → Options → Save. Make sure the AutoRecover location points to a local drive, not a network path.
• Stick to .xlsx format for anything important. The old .xls binary format corrupts far more easily.
• On OneDrive, disable "Files On-Demand" for folders with active Excel files. A partially downloaded file triggers this exact error every time.

Verification

The fix worked when:

• Excel opens the file with no repair dialog.
• All sheets are present and the data matches what you expect.
• Formulas calculate correctly — hit Ctrl+Alt+F9 to force a full recalculation.
• Charts and pivot tables render without errors.

Save the recovered file under a new name immediately. Don't overwrite the original until you've confirmed the data is intact.