The error message "Make sure that the built-in administrator account login and password for the target host are correct" typically occurs during a migration process when Plesk is unable to authenticate with the target server using the provided administrator credentials.

Here are steps to resolve this issue:

1. Verify Administrator Credentials:

   • Double-check the login and password for the built-in administrator account on the target host. Ensure that they are correct and have the necessary privileges.

2. Confirm Administrator Access:

   • Ensure that the built-in administrator account on the target host has the necessary permissions and is allowed to perform administrative tasks.

3. Check for Account Lockout:

   • Verify that the administrator account on the target host is not locked out due to multiple failed login attempts.

4. Test Remote Access:

   • From the source server, try to establish a remote connection to the target server using the same administrator credentials. This can help verify if there are any connectivity issues or if the credentials are indeed incorrect.

5. Verify Remote Desktop Protocol (RDP) Settings:

   • Ensure that Remote Desktop is enabled on the target server, and the administrator account is allowed to log in via RDP.

6. Firewall and Security Software:

   • Check if there are any firewall rules or security software on the target server that might be blocking remote access.

7. Confirm UAC Settings:

   • On the target server, ensure that User Account Control (UAC) settings allow for remote administration.

8. Check for Special Characters in Password:

   • If the password contains special characters, ensure that they are being correctly interpreted during the migration process. Consider using a password without special characters for testing purposes.

9. Try Alternative Credentials:

   • If possible, try using alternative administrator credentials to see if the issue persists.

10. Recreate the Administrator Account (if applicable):

    • If none of the above steps work, consider recreating the built-in administrator account on the target server, ensuring it has the necessary privileges.

11. Contact Plesk Support:

    • If the issue remains unresolved, consider reaching out to Plesk support for further assistance. They can provide specific guidance based on your server's configuration.

Remember to always keep backups of your data and configurations before making significant changes to ensure you can revert to a stable state if needed.

The error message "Make sure that the built-in administrator account login and password for the target host are correct" during a migration in Plesk suggests that there is an issue with the authentication credentials for the target host's administrator account. This account is essential for Plesk to access and perform actions on the destination server during the migration process.

To address this issue, follow these steps:

1. Verify Administrator Account Credentials:

   • Double-check the username and password for the built-in administrator account on the target (destination) server. Ensure that they are correctly entered in the Plesk migration settings.

2. Ensure Administrator Account Is Active:

   • Ensure that the built-in administrator account on the target server is active and not locked or disabled. Reset the password if necessary.

3. Use a Strong Password:

   • Ensure that the password for the administrator account meets complexity requirements and is sufficiently strong. Avoid special characters that might cause issues with password input.

4. Administrator Privileges:

   • Confirm that the administrator account has the necessary privileges to perform tasks related to the migration, such as creating accounts, databases, and configuring services.

5. Server Connectivity:

   • Ensure that the target server is reachable from the source server and that there are no network or firewall issues blocking the connection between them.

6. Remote Desktop (RDP) Access:

   • If you're migrating to a Windows server, verify that Remote Desktop (RDP) access is enabled and functioning correctly. Test connecting to the target server via RDP to ensure it's accessible.

7. Plesk License and Version Compatibility:

   • Ensure that the Plesk license on the target server is valid and compatible with the source server's Plesk version. Migrations between different Plesk versions might require additional steps.

8. Plesk Migration Manager:

   • Ensure that both the source and target servers have the Plesk Migration Manager extension installed and up-to-date.

9. Test the Administrator Account:

   • To validate the administrator account's credentials, you can attempt to log in directly to the target server using Remote Desktop (for Windows) or SSH (for Linux). This can help confirm that the credentials are correct and that there are no issues with the account.

10. Consult Plesk Documentation:

    • Refer to Plesk's official documentation or knowledge base for specific troubleshooting steps related to migrations.

11. Contact Plesk Support:

    • If the issue persists and you're unable to resolve it, consider reaching out to Plesk support for further assistance. They can provide specific guidance based on your server's configuration.

Addressing authentication issues during migrations is crucial to ensure a smooth and successful transfer of data and settings from one server to another.