Unable to open the Plesk Extensions page: Unable to connect to the extensions catalog: Connection timed out

Symptoms

• The Extensions page cannot be opened with one of the following messages:

  PLESK_ERROR: Error: Unable to connect to the extensions catalog: Connection timed out after 30001 milliseconds

  ---

  PLESK_WARN: Internal server error Retry

  ---

  PLESK_INFO: 504 Gateway Timeout

• When installing an extension via a command-line interface, the operation fails with one of the following error messages:

  # plesk bin extension --install support-access
  Resolving timed out after 30000 milliseconds

  ---

  # plesk bin extension --install support-access
  Connection timed out after 30000 milliseconds

• When installing Plesk Migrator using Plesk Installer, the operation fails with one of the following error messages:

  CONFIG_TEXT: Error: Unable to install the extension: Executing /usr/local/psa/tmp/moduleR2GaBC/plib/scripts/pre-install.php failed: It is impossible to install Plesk Migrator on Linux servers via Plesk extensions catalog. Please install it by means of Plesk Installer.

  ---

  CONFIG_TEXT: The component plesk/pmm is not available.

• The Plesk Home page loads slow.

• The following error messages appear in /var/log/plesk/panel.log:

  CONFIG_TEXT: INFO [panel] Retrieving Extensions Catalog feed: https://ext.plesk.com/api/v4/packages?platform=unix
  ERR [panel] PleskException: connect() timed out!
  file: /usr/local/psa/admin/plib/Extension/Catalog.php

  ---

  CONFIG_TEXT: Error in cURL request: Could not resolve host: check-updates.plesk.com

  ---

  CONFIG_TEXT: ERR [extension/catalog] Failed connect to ext.plesk.com:443; No route to host

Cause

Plesk Extensions URL ext.plesk.com is not reachable from the Plesk server:

# wget https://ext.plesk.com
http://ext.plesk.com/
Resolving ext.plesk.com (ext.plesk.com)... failed: Name or service not known.
wget: unable to resolve host address 'ext.plesk.com'

# wget https://ext.plesk.com
http://ext.plesk.com/
Resolving ext.plesk.com... 185.87.24.173
Connecting to ext.plesk.com|185.87.24.173|:80... failed: Connection timed out.

Resolution

1. Connect to the Plesk server via SSH.

2. Open the file /etc/resolv.conf in a text editor. In this example, we are using the vi editor:

   # vi /etc/resolv.conf

3. Comment out the lines with nameserver by placing a # (hash) character at the beginning of the line:

   CONFIG_TEXT: #nameserver 203.0.113.2
   #nameserver 203.0.113.3

4. Set Google DNS as DNS resolver:

   CONFIG_TEXT: nameserver 8.8.8.8

5. Save the changes and close the file.

6. Check the Extensions page in Plesk.

   If the Extensions page is still not loading, make sure that intermediate firewall is not blocking the connection to ext.plesk.com. Contact your network administrator for assistance.