Fix Chrome ERR_TUNNEL_CONNECTION_FAILED Proxy Error - Fix Windows Defender Real-Time Protection Stuck-Fix Let's Encrypt Certbot Renewal Failures

Updated 2026-06-13 15:10:51security-tools
Fix Chrome ERR_TUNNEL_CONNECTION_FAILED Proxy Error - Fix Windows Defender Real-Time Protection Stuck-Fix Let's Encrypt Certbot Renewal Failures
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.