Fix Excel Crashing on Mac with SIGKILL Code Signature Invalid Error
Question details
Microsoft Excel immediately crashes upon launch on macOS, displaying a 'SIGKILL (Code Signature Invalid)' error in the crash report.
- Product
- Microsoft Excel
- Device & OS
- macOS 12.6.6
- Scenario
- Attempting to open the Microsoft Excel application on a Mac computer.
- Observed behavior
- The application fails to open and immediately generates a crash report citing 'SIGKILL (Code Signature Invalid)'.
Ensure you have your Mac administrator password ready, as you will need administrative privileges to run the Disk Utility First Aid process.
Run Disk Utility First Aid and Update Excel
Repairing disk permissions and verifying the file system can often resolve code signature invalidation errors without needing to completely reinstall the application.
The macOS operating system checks application code signatures to ensure software integrity. If disk permissions are corrupted, Mac may incorrectly invalidate Excel's signature, causing an immediate SIGKILL crash.
Go to 'Applications', open the 'Utilities' folder, and double-click on 'Disk Utility'.
Select your Mac's startup disk from the left sidebar, click the 'First Aid' button at the top of the window, and click 'Run' to begin the repair process.
Once First Aid is complete, restart your Mac. Open Microsoft AutoUpdate to check for and install the latest compatible Excel update.
Clean Reinstall Microsoft Excel
If the error persists after repairing the disk, the Excel application files are likely deeply corrupted and require a fresh installation.
Try WPS Office for Mac as a Reliable Alternative
If Microsoft Excel continues to crash or you want to avoid lengthy troubleshooting steps, WPS Office provides a lightweight, stable, and completely free alternative to keep your spreadsheet work moving without interruption.
Frequently Asked Questions
Does the SIGKILL Code Signature Invalid error mean my Mac has a virus?
No. While it sounds alarming, this crash report simply means the macOS operating system detected a mismatch or corruption in the application's digital signature, preventing it from running. It is rarely an indication of a malware infection on its own.
Will running Disk Utility First Aid delete my Excel spreadsheets?
No. The First Aid tool only verifies and repairs the Mac file system and disk permissions. It does not touch, modify, or delete your personal files, documents, or spreadsheets.
How do I ensure I am downloading a trusted Microsoft Excel installer?
Always download the Excel installer directly from your signed-in Microsoft account dashboard (office.com) or the official Mac App Store. Avoid third-party software hosting sites to guarantee the software's authenticity and prevent code signature errors.
