Several customers have been complaining of the same issue. “A new delivery condition in the seller proposal must be accepted in order to continue.”
We have been in contact with shopify support since the major outage on Tuesday October 25th at 1:00 pm with no solution.
From support just now "
From here, I want you to test it out for yourself just to check if this error has been resolve already. If not then this have got to do with your customer and the device they are currently using. So for that to get corrected you can just ask them to perform a local troubleshooting steps on their end and try to place an order again just to see if that works out on their end. Since it worked out in my end."
I have asked several customers to clear cache etc. and also to try a new browser and they still could not order…
The only thing that works is to create a draft order and invoice manually.
There is clearly an issue with the Shopify UI since the outage.