We recently had a donor give elsewhere because she could not find the field that was missing in the form. This is only a problem with the credit card section of the form, which does not highlight the expiry date or CVC if they are missing (it will highlight the credit card number more or less however). This is probably a Stripe thing, which ideally they would add the red highlight to the other fields, but otherwise it would be great if instead of saying "Please complete the entire form" when you try to click on the greyed out Donate button (which gives you no indication of WHERE you are missing information), it instead said something like "Please complete the entire form, including the credit card number, Expiry Date and CVC", or if there was a way to let people know these THREE fields are required.
The first time I tried filling out the form for myself, I also had missed the CVC and had a hard time figuring out what was missing, so I assume that this is not the first time that this has happened.