Errors on the last page of registration normally happen due to some of the fields not being filled in with the appropriate information. Ensure that you fill out all mandatory fields with the information that is required.
You can also check if you have accepted the Terms & Conditions prior to attempting to complete your purchase. Without accepting the Summit's T&Cs you wouldn't be able to proceed. This field should be visible at the bottom of the page if you haven't accepted them previously. If you can't see it, please open an incognito browser and try checking out again.
Finally, it is also important to remember where you have started checking out. If you entered your name on any of the fields within the Summit (see Screenshot below for one example), you would automatically accept the T&Cs. If you still encounter issues on the last page of registration, we would advise that you get in contact with the Event Organizing team.