since 10th Oct 2017 installed any Agile Modules from back-end permissions become to folder/0777 and files/0666
permissions should be folder/0755 and files/0644
It was happened by using FTP client to do the changes from Agile supporter during testing.
Then the server status is unstable.
Once again, on 31 Nov most of site permissions become to 0750 not work during using FTP client.
The HOST said the permission is being set up by Prestashop or modules by default. And changes by using FTP client
PrestaShop 1.7.2.2 PHP 7.1
Multiple Seller/Vendor Module 3.7.2.2
and other moudles