Fix 'Windows Security Module Not Found' Antivirus Error - How to Fix Windows Defender Version Mismatch Error-Resolve Task Scheduler Stuck on Repair Checklist

Updated 2026-06-13 19:10:27backup-recovery
Fix 'Windows Security Module Not Found' Antivirus Error - How to Fix Windows Defender Version Mismatch Error-Resolve Task Scheduler Stuck on Repair Checklist
Before changing system settings, save your work and note the exact error text so you can compare results after each step.

Extra verification checklist

  • Restart the affected app after changing permissions or configuration files.
  • Test the same workflow in a clean browser profile or a temporary user account.
  • Compare the result on another network if the error may be connection related.