Not sure if you have asked this question under a different ID ? If not another member has faced the same issue.
Today is eBay's maintenance day and many things are not possible or go awry from time to time, especially in our early hours in the morning when it's still late evening the day before in CaliforniA, where eBay's HQ is based, and when most updates and tweaks to the system are made.
Try again later on today, also remember to make an offer now you have to provide an instant payment so the method, bank / credit card, has to be added to your eBay account.
@silverhead2013
