Some other 3rd party Wordpress plugins and themes may conflict with Handsome Checkout predesigned templates.
Known ones are:
- WooCommerce Smart Checkout from Apppressor (temporary solution: you need to disable it)
- OptimizePress (we are working to make it compatible with Handsome Checkout)
- Inline Styles plugin - this plugin prevents the CSS for the Handsome Checkout page from loading (solution: please disable this plugin)
If you can't identify the reason of the problem, please send us the name of the theme and the list of the plugins, you are using.