Some of us don't want customers to be able to buy products that are out of stock. OpenCart has an option (AP > System > Settings > {Edit store} > Option > Stock, mark Stock Checkout as No) that disallows customers to check out if they have an out of stock item in their shopping cart. This is a start, but for many of us it's just not consequential!
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Supported Themes
The extension support default theme by default. It may not work due to changes you make or other extensions you have installed. You can contact us about errors or other themes.
Downloads
When you purchase a Premium Membership or a Single Extension, you will have as many as purchased quantity a Store License for each extension.