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:

  external server 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

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.

Note: external functions in Plesk expect the file size of the /etc/psa/private/secret_key file to be exactly 16 bytes.

Resolution

1. Connect to the server via SSH

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

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

3. 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