"QuickBooks has encountered an issue and needs to be shut down" and soon after the computer immediately shuts down. This blog shall explain the various causes and solutions for QuickBooks Error code 4120. So, keep reading.
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Update QuickBooks: Ensure you are using the latest version.
Verify Company File: Run the Verify Data utility to identify and fix data integrity issues.
Rebuild Data: Use the Rebuild Data utility to resolve data-related problems.
Check for Special Characters: Remove any special characters from your company name.
Restore a Backup: If the issue persists, restore a backup of your company file.

Regards,
Peter