If the installation stalls and fails to respond after a few minutes, or if WordPress gives you an error message, you are suffering from PHP configuration limits that are set too low to complete the process. You should contact your hosting provider and ask them to increase those limits to a minimum as follows:
Besides this, you can upload the theme using your FTP client, upload the non-zipped theme folder into the /wp-content/themes/ folder on your server.
Viewing System Status
You can also view some of your WordPress system settings by going to the eLab Theme System Status page. (Click on eLab > System Status in the WordPress menu.) This page will provide information about your WordPress environment and your server environment.
Any items that require your attention will be highlighted in yellow