The formula points to a temporary Outlook attachment copy on one user’s computer—not to the SharePoint workbook—so preserve the current evidence, identify when that reference appeared, and then change its source to the correct SharePoint workbook.
The formula:
=+'C:\Users\Lizelle\AppData\Local\Microsoft\Windows\INetCache\
Content.Outlook\H4SFQZDT\[K3 Sibanye Scorecard - FY2026.xlsx]Total K3'!$K56
is an external-workbook formula. It retrieves cell K56 from worksheet Total K3 in K3 Sibanye Scorecard - FY2026.xlsx. Content.Outlook is Outlook’s secure temporary attachment location ^1^. This strongly indicates that the formula was created or redirected while Excel was using a copy opened directly from an Outlook attachment. It does not, by itself, establish who performed the action.
Preserve and audit the evidence first
Do not repair or restore the production workbook until copies of the relevant versions have been retained.
- In Excel, select the affected cell.
- Select Review > Show Changes, or right-click the cell and select Show Changes.
- Record or screenshot:
- Who is listed
- Date and time
- Previous formula
- Replacement formula
Show Changes reports who changed a cell, when it changed, and its previous value; its available history covers up to 365 days ^2^.
- In the SharePoint library, select … beside the workbook and then Version history.
- Open the versions immediately before and after the formula changed. Save copies under different names for investigation.
SharePoint versioning records when a file version changed and who saved it, and permits comparison or restoration ^3^. Because AutoSave is off, another user’s edits might only be merged when someone manually saves. Therefore, the account shown for a saved version should not automatically be treated as proof that the same person manually typed every formula in that version. Microsoft documents that turning off AutoSave delays co-author changes and increases merge-conflict risk ^4^.
Repair the link
After retaining the evidence:
- Open the affected workbook from its SharePoint location, not from email or a downloaded attachment.
- In Excel desktop, select Data > Queries and Connections > Workbook Links.
- Locate
K3 Sibanye Scorecard - FY2026.xlsx.
- Select More Commands (…) > Change source.
- Browse to and select the authoritative source workbook in SharePoint.
- Select Refresh, and verify that the linked value matches
Total K3!K56.
- Save the workbook back to SharePoint.
Excel’s supported procedure for a broken or incorrect external reference is Workbook Links > Change source ^5^.
If only this one formula should change, select the cell and replace the temporary path in the formula bar with the correct source reference. Use Change source only if every reference to that source workbook should be redirected.
Do not select Break links: that converts linked formulas to their current values and cannot be undone ^5^.
If the last known-good version contains the correct links throughout:
- SharePoint library > … beside the file > Version history.
- Open the earlier version first and verify its formulas.
- From that version’s menu, select Restore > OK.
SharePoint retains the existing history and makes the restored copy the latest version ^6^.
Prevent recurrence
- Stop distributing editable workbook attachments; send the SharePoint link instead.
- Have everyone open the same SharePoint file rather than local or email copies.
- Enable AutoSave for supported SharePoint workbooks. Microsoft recommends it for co-authoring because changes are then visible in real time ^7^.
- Keep SharePoint versioning enabled and periodically review Workbook Links for local paths containing
C:\Users\ or Content.Outlook.
References
- Quick Print stops printing PDF attachments in Outlook Desktop | Microsoft Support
- Show changes made in a workbook | Microsoft Support
- How versioning works in lists and libraries | Microsoft Support
- What happens if I turn off AutoSave? | Microsoft Support
- [Windows](#tab/windows)
- Restore a previous version of an item or file in SharePoint | Microsoft Support
- Best Practices for Coauthoring in Excel | Microsoft Support