Hi lawkwok,
I know it’s late, but I wrote an article about this: https://support.woothemes.com/hc/en-us/articles/205189575
I hope that this helps.
Thanks!
Be sure to double-check whether you’re adding costs based on specific shipping classes within the Flat Rate method. If you are, you need to make sure that each product you have available for sale is linked to a shipping class. If you have some products not linked to a shipping class, but you’re charging based on shipping classes, the checkout process won’t be able to determine the available method(s).
I hope that this helps.
Be sure to double-check whether you’re adding costs based on specific shipping classes within the Flat Rate method. If you are, you need to make sure that each product you have available for sale is linked to a shipping class. If you have some products not linked to a shipping class, but you’re charging based on shipping classes, the checkout process won’t be able to determine the available method(s).
I hope that this helps.
