Jupyter Kernel Not Starting: Quick Fixes - Fix Event ID 4625 Failed Logon in Windows Security Log-Resolve Windows Defender Version Mismatch After Update

Updated 2026-06-13 15:59:41cloud-software

Jupyter Kernel Not Starting: Quick Fixes - Fix Event ID 4625 Failed Logon in Windows Security Log-Resolve Windows Defender Version Mismatch After Update

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.