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
In current version, the after order booking data is not managed properly so the rooms do not get free once an order is canceled.
So you will have to go to the order which is canceled and delete the rooms in that order.
But we are working on this issue in our new version and hopefully, you will get the solution in the upcoming version which will be launch very soon.