Error accessing Plesk from WHMCS via API: Customer with external id ‘whmcs_plesk_XX’ is not found in panel

Symptoms

Cannot access Plesk from WHMCS via API as a customer or change password:

Error code: 1013. Error message: Customer with external id 'whmcs_plesk_XX' is not found in panel.

Error code: 1013. Error message: Customer with email '[email protected]' is not found in panel. Please contact your service provider.

Cause

The external_id entry is missing in psa.clients MySQL table.

Resolution

Note: if the issue appears on WHMCS integrated with Plesk Multi Server, this database update should be done on the management node side.

1. Log in to the server via SSH

2. Create a backup of psa database:

   # plesk db dump > psa.current.sql

3. Access Plesk database from command line:

   # plesk db

4. Update the following value:

   update clients set external_id='…