Unable to access Plesk Installer in a web browser: HTTP ERROR 502

Symptoms

• When accessing Plesk Updates page from Plesk > Tools & Settings > Updates, it does not load with a blank page or one of the error messages below:

  PLESK_INFO: 502 Bad Gateway

  ---

  PLESK_INFO: HTTP ERROR 502
  203.0.113.2 is currently unable to handle this request.

• Option Access Plesk Installer via the Plesk hostname and port is enabled at Tools & Settings > Update Settings.

Cause

Network misconfiguration.

Resolution

1. Log in to Plesk.

2. Go to Tools & Settings > Update Settings and uncheck the option Access Plesk Installer via the Plesk hostname and port.

Alternatively, run this command in a command prompt on your Windows Server:

C:\> plesk bin settings --set installerProxyMode=false