Hello,
after installation of any extension, alert will appear. Unexpected token '<', " "... is not valid JSON
after reload, extension is installed with "success" message.
Also that appeared during the installation via ftp and kickstart.php (by akeeba.com)
My setup:
Joomla! 4.2.2 Stable
php 8.0.22
Sp page builder Version: 3.8.7
Helix-ultimate 2.0.11
maria database 10.3.27