This issue is most often caused by the program running out of the allowed memory. This is because PrestaShop 1.6 is a bit more memory intensive than previous versions.
To resolve the PrestaShop 1.6 blank white screen, please follow the steps below:
1. Login to your Cpanel.
2. Under Software and Services click Select PHP Version.
3. Choose the PHP version from the drop-down menu and click on Switch To PHP Settings.
4. Select the PHP memory_limit variable and choose from the drop-down menu at least 128MB.
5. Click Apply.