Set Windows Defender Threat Service to Automatic Startup - How to Fix Outlook Authentication Failed Error 0x80048820-Outlook Won't Load Past Profile Screen – Troubleshooting

Updated 2026-06-19 01:52:17macos-help
Set Windows Defender Threat Service to Automatic Startup - How to Fix Outlook Authentication Failed Error 0x80048820-Outlook Won't Load Past Profile Screen – Troubleshooting
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.