When installing PrestaShop 1.7 via Softaculous auto-installer the following error is displayed: Unable to generate new_cookie_key, hence can not install Prestashop 1.7
The problem isn’t with PrestaShop, but with the Softaculous application. Softaculous creates a temporary file in your installation folder and then uses curl call to access that file and generate the cookie key needed for autologin. Softaculous failed to create keys in this scenario, most likely because of an issue with the .htaccess file in the installation or parent directory.
To fix this, simply open File Manager and navigate to the destination directory then rename the .htaccess file.
or from the terminal:
mv .htaccess .htaccessOLD
Then go back to Softaculous and run the installation process again.
If you are still having problems, open a support ticket to Softaculous here: https://softaculous.deskuss.com/open.php