On the checkout, I get an error "Checkout is currently unavailable due to technical problems" or "Checkout not working"

This can be due to many reasons. Most common solutions for fixing that are:

1. ) Try clearing the cache of your current browser,
2. ) Try opening the checkout from the different device and browser
3. ) Checkout might be disabled so make sure that you enable it in the checkout settings
4. ) You are still on free trial. In order for the checkout to be working correctly, you need to be subscribed to a paid plan.
5. ) Check if shipping settings in your store are setup correctly