For me, the booking was IMPOSSIBLE to do due to website glitches (because I was booking award in J). If it's for Y, it does allow me to proceed.
So I called the call center, and the rep created the booking for me, but I have to complete the payment online. I was able to do so without issues.
She also gave a tip to use Chrome, instead of Firefox or IE (gasp). She said people have been reporting better success rate when completing it with Chrome.