To make QloApps compatible with PHP 8, you can use a PHP compatibility check tool to update the deprecated and removed functions or you can cross-check PHP 8 changelog and update functions as required.
We suggest you use a compatibility tool for easier migration to PHP 8.
@max This issue is caused when following file is corrupted. Please delete it and login to your back office to force download of this file.
File location: qloapps_root_directory/config/xml/default_country_modules_list.xml