If you have created multiple shipping presets for your store, you may find that a customer reaches out to inform you that they are seeing the following error when selecting a destination in your store's checkout:
The cause of this error is that the customer is trying to purchase two or more items from your store at once - and it happens to be that the items are in different shippings presents where the is no shipping option in common between the presets.
The solution is to ensure that, if you have multiple presets, that there is an overlap in the shipping option between each of the presets. For example, if you have an item in a shipping preset that ships to the UK with the shipping option 'next day delivery' - you'll want to ensure that all other presets also support shipping to the UK, with the same option of 'next day delivery' - otherwise the customer will not be able to purchase both items at the same time.
Note to that a temporary solution, depending on your use case, could be to ask that the customer orders the items separately, which would also bypass this potential issue. This may be your only option if you have a special use case with regards to shipping.