I constantly get the error "Store URL is not valid". What's wrong?
If your input 'Store URL' is in the required format i,e,
https://www.mystore.com/ or
http://www.mystore.com/ and you are still constantly getting a Store URL invalid error, it is likely that your Apache configuration is not set to allow Magento .htaccess to work.
To fix this issue, please do the following:
Locate your Apache configuration file. It is usually at located at one of the following locations on your server:
/etc/apache2/httpd.conf
/etc/apache2/apache2.conf
/etc/httpd/httpd.conf
/etc/httpd/conf/httpd.conf
Enable rewrites, by adding option 'AllowOverride All' as in the following:
<Directory /var/www/html/yourMagentoDirectory/>
Options Indexes FollowSymLinks
AllowOverride All
Require all granted
</Directory>
'yourMagentoDirectory' path must match the location of your Magento installation on your server file system. After changing the configuration, restart the Apache server.