i've tried to add a custom pdf invoice generator.
I've copied the template default_no_vat in another direcotry, then i've selected the new template from the trop down menu in panel.
When i'll try to create a new invoice, after adding objects and click on Save and Finalize nothing heappen.
In the log i'll get the following error
mod_fcgid: stderr: PHP Fatal error: Class 'PDFInvoice_custom' not found in /usr/local/ispconfig/interface/web/billing/invoice_edit.php on line 303, referer: https://www.domain.tld:8080/index.php