Zen Cart’s page loading time is affected by a variety of factors. This can make troubleshooting certain page speed related issues quite difficult at times. Before you get started on this problem, you should check to see if the storefront of your zen cart site is slow as well. If the same slowness shows up there, then your Zen Cart version server is not the problem, and this tutorial will not help you solve your problem. Your web server may be unable to communicate with the Zen Cart version server, either due to slowness, or the complete lack of a response. Try talking to your hosting company about why your server can’t access ping.zen-cart.com, and the possibility that there may be a DNS problem on your server.
If the page loading issues are occurring only in your admin area, however, keep on reading.
The problem is most likely occurring when your zen cart tries to contact the Zen Cart version server to check for updates after you first log into your admin area. If the server is unavailable, or unreachable, the admin screen will take a while to load while waiting for a response. You can easily fix this issue using one of two methods.
The first is to log into your admin area, navigate to Admin–> Configuration–> My Storeand disable the version checking here setting ‘Show if version update available’ to ‘0/false/off’.
The second option should only be used if you cannot log into your zen cart admin area at all. In this case, open your /admin/includes/local/skip-version-check.ini file in your favorite plain text editor, and find this code:
Change the ‘on’ to ‘off’, save the file, and upload it to your zen cart server.