Unable to install applications from APS catalog: Server Error 502 Bad Gateway

Symptoms

• An attempt to install WordPress from Domains > example.com > Install Application > More Apps > Featured > WordPress > Install fails with:

  Server Error
  502 Bad Gateway
  Web server received an invalid response while acting as a gateway or proxy server.

• Installing WordPress with the WP Toolkit does work correctly.

• The same behavior also occurs with Magento and osTicket from the application catalog.

• Server runs AlmaLinux or CloudLinux 8 OS.

Cause

This is the Plesk bug PPPM-14094. Which will be fixed in future Plesk Updates.

Resolution

Until the bug be fixed, use one of the following workarounds:

• Install WordPress from Domains > example.com > Install Application > WordPress.

  Note: The usage of WP Toolkit needs to be enabled for this to be visible to the customer.

• Retry the installation from More Apps catalog as this was observed to work after some attempts.