0 Class "PHPMailer" not found

Hi there,
Joomla 4.2.6
Acymailing Enterprise 5.11.3
(auto)subscribe plugin: activated
License: active

Since Joomla 4 migration I get this error. Looks like the class in jMail_J25.php can't be found????
0 Class "PHPMailer" not found

Looks like the class in jMail_J25.php can't be found????

Any clue?
Many thanks,
Antoine

Hi,