HeyI keep getting this error when I try to add a product to the cart.Link to my store https://simonstop.com/
May you explain which type of error do you face? I have checked your link, I have successfully added item in cart.
I got the same error.
When I clicked the "Add To Cart" button I go the "There was an error while updating your cart. Please try again." error. When I refresh the items added to the cart which is not ideal. Please see the attachment.