Error in Plesk: errors in configuration templates: Wrong variable to subsitute: os file

Updated January 14, 2021 11:40

kb: technical ABT: Group A

Symptoms

Plesk shows the following error:
PLESK_ERROR: New configuration files for the Apache web server were not created due to the errors in configuration templates: Template processing failed: file = /usr/local/psa/admin/conf/templates/default/webmail/webmail.php, error = Template_Exception: [Template_Variable_Server_WebServer] Wrong variable to subsitute: os file: /usr/local/psa/admin/plib/Template/Processor.php
Atmail webmail is used for domains from MySQL query below:

# plesk db "select name from domains where id in (SELECT objectId FROM Configurations WHERE status='error' and description like '%Wrong variable to subsitute: os file%') ;"

Atmail Open is supported by both Plesk for Linux and Plesk for Windows, versions until 11.5.

Log into Plesk.
Switch to another webmail for domains from the MySQL query under Domains > example.com > Mail Settings > Webmail.

Note: install additional webmail if required How to install and manage webmail in Plesk?