Hi
please i try grand v 4.30 on my local develop PC and i can do an order and then confirm it from admin, now i have upload site to server (digitalocean) and i try to do same steps i did in local but i can't complete order in the cart page i got "Calculated during checkout" and  shwn i press checkout button i redirect to onepagecheckout and in this page if i click Continue button it redirect me to cart page again it's not let me go to next step to enter Shipping address

so please how can i make it works

Looks like your issue may be similar to Phil's topic, re:

https://grandnode.com/boards/topic/5c4847a70a0af1213c873c54/error-at-onepagecheckout

Hello Ahmed,

Please check the topic which Bill mentioned above. You can jump to my last post here. And please post us results of this test.