Plesk server shows "Connection blocked" error message at Plesk 360 or WebPros Dashboard sides

Symptoms

• Plesk server shows "Connection blocked" error message at Plesk 360 or WebPros Dashboard sides:

  PLESK_ERROR: The server is configured so that it is impossible to establish a connection. Possible causes:
  * Platform 360 IP addresses are filtered out for Administrator’s access (instructions)
  * Remote access via Plesk API is disabled in panel.ini (instructions)
  
  Make sure, the access from the following IP addresses is allowed: 34.254.37.129, 52.51.23.204, 52.213.169.7.
  
  To connect the server successfully, please adjust the corresponding configuration settings. When done, click the button below to check the connection.

• 403 error message can be found in Plesk access log with Plesk 360 IP address mentioned:

  # grep -E "api/v2/(server|clients|domains)" /var/log/plesk/httpsd_access_log
  34.254.37.129 - - [12/Aug/2026:10:14:47 +0100] "GET /api/v2/clients HTTP/1.1" 200 228 "-" "axios/1.18.1" "-"'/modules/rest-api/public/index.php/v2/clients' '' '/usr/local/psa/admin/htdocs'
  34.254.37.129 - - [12/Aug/2026:10:14:47 +0100] "GET /api/v2/domains HTTP/1.1" 200 33 "-" "axios/1.18.1" "-"'/modules/rest-api/public/index.php/v2/domains' '' '/usr/local/psa/admin/htdocs'

• There are no blocks from Web Application Firewall, Fail2Ban or any other firewalls.

Cause

Plesk bug with ID EXTPLESK-14219 which stands for the change in REST-API work.

Resolution

Until the bug is fixed, enable Server information permission at Tools & Settings > Restricted Mode Settings > Administrative Tools page in Plesk interface.

If the Restricted Mode Settings page is missing at Tools & Settings page, then follow the next steps to workaround it:

1. Connect to the server via SSH.
2. Create Plesk database backup.

3. Check for id of manage_server_info parameter:

   # plesk db "SELECT * FROM Permissions WHERE permission IN ('remote_access_interface','manage_server_info') \G"
   
   *************************** 1. row ***************************
   id: 1
   permission: manage_server_info
   value: false

4. Enable Server information permission based on the found id:

   # plesk db "UPDATE Permissions SET value='true' WHERE id=1 AND permission='manage_server_info'"