500 Internal server error on Domains page: Message Cannot destructure property 'screenshotUrl' of 'data.site' as it is null

Symptoms

• Plesk Obsidian running on a Linux-based operating system
• The installed Monitoring extension in Plesk is not version 2.9.1.

• When clicking on some domains in Plesk > Domains, one of the following errors is displayed:

  PLESK_ERROR: Internal server error

  PLESK_ERROR: Message Cannot destructure property 'screenshotUrl' of 'data.site' as it is null.

• The size of /etc/psa/private/secret_key file is more than 16 bytes:

  # ls -lash /etc/psa/private/secret_key
  4.0K -rw------- 1 psaadm root 17 Mar 21 13:11 /etc/psa/private/secret_key

• The permissions of the /etc/psa/private/secret_key file are incorrect and the plesk repair fs -n command returns the following output:
  

  CONFIG_TEXT: Checking Linux system files
  There are incorrect permissions on some items:
  /etc/psa/private/secret_key ....................................... [ERROR]

Cause

The file /etc/psa/private/secret_key was opened and saved manually by using a command-line text editor, which added one extra byte to the file or its permissions were changes in a manual way.

Note: Internal functions in Plesk expect the file size of the /etc/psa/private/secret_key file to be exactly 16 bytes and to have the following permissions and ownership:

# [root@server ~]# ls -lash /etc/psa/private/secret_key
4.0K -rw-------. 1 psaadm root 16 Oct 24 2022 /etc/psa/private/secret_key

Resolution

1. Connect to the server via SSH

2. Fix the permissions of the /etc/psa/private/secret_key file by executing the following command:
   

   # plesk repair fs -y

   
   

   Note: If the permissions and ownership are the only issue and the file size is correct, this action in itself may resolve the entire issue and the subsequent steps will not be necessary

3. Create a backup of the original file by executing the following command:

   # cp /etc/psa/private/secret_key /etc/psa/private/secret_key.bak

4. Remove the last byte from the file and replace the original by executing the following command:

   # head -c -1 /etc/psa/private/secret_key > secret_key.new
   # mv secret_key.new /etc/psa/private/secret_key

Additional information

Unable to open any domain in Plesk after Monitoring extension update to 2.9.1: Cannot destructure property 'screenshotUrl' of 'data.site' as it is null – Plesk