Check the VAT rates you have set.
Check in the "Modifiers" section that the Min is lower than the Max.
Always have a number in the "Max" section.
Check that there are no infinite loops.
It's the modifier that must be associated with the product, not the product with the modifier.
Example: Ketchup sauce, should be associated with the "Choose your sauce" modifier, then the latter should be associated with "French fries" in "Products".
And no, in "Products", Ketchup must not have any "Modifiers", otherwise it will create an infinite loop, where the customer chooses French fries, is offered the choice of sauce, selects Ketchup, then is again offered the choice of sauce, and if he chooses Ketchup again, he will go round in circles.
If the problem persists, contact support via:
e-mail : support@rushour.io
the question mark at top right
WhatsApp : +44 20 3398 9394.