Go to Admin page and upload/install the zip file with Module Loader.
Go to your order history (https://www.quickcrm.fr/mobile/en/order-history).
Then click on your latest valid order.
You will find a download link on the product name.
You should first have a look at your PHP/Apache error log for more details on the error.
It is likely that permissions are not correct in your custom, cache, mobile or service folders, and default_permissions are not set correctly in config.php.
All files in custom folder and subfolders should have the same permissions as index.php in your CRM root folder.
All folders in custom folder and subfolders should have the same permissions as the cache folder. The owner of these folders and files must be the Apache User. If that not the case, change the owner of these files and folders. Once you have solved the issue, you should update config.php so that the problem does not happen again next time you install a new version of the server module. You should first make sure that the apache user and group are set in config.php (default_permissions user and group).
You should have 'user' => 'Apache user', // for example 'www-data' in default Ubuntu configuration
'group' => 'Apache group', // for example 'www-data' in default Ubuntu configuration If permissions of index.php are 775, you should define : 'dir_mode' => 509,
'file_mode' => 436, If permissions of index.php are 755, you should define :
'dir_mode' => 493,
'file_mode' => 420,