zhizhu
Home / office-tools / Fix Windows Defender Can't Connect to Internet Error - ERR_TUNNEL_CONNECTION_FAILED Troubleshooting Guide-Fixing Common Certbot Nginx Plugin Failures

Fix Windows Defender Can't Connect to Internet Error - ERR_TUNNEL_CONNECTION_FAILED Troubleshooting Guide-Fixing Common Certbot Nginx Plugin Failures

2026-06-13 14:47:19
Fix Windows Defender Can't Connect to Internet Error - ERR_TUNNEL_CONNECTION_FAILED Troubleshooting Guide-Fixing Common Certbot Nginx Plugin Failures

Result check

  • Keep one change per test run so you know which step helped.
  • Undo temporary changes after the issue is confirmed.