Hello 'schow69',
If you are in your ebay Messages Inbox and have opened in front of you a message to which you
wish to reply, there should be a light blue Reply button across the bar at the top as well as a
yellow and black Respond button to the right of the body of the message.
Do you not have that?
If not, it can only be a temporary ebay 'glitch', of which there have been a great many lately. All I can
say is that the 'reply/response' feature will reappear soon enough.
It could also be a problem if you are using a hand-held device, as many features of ebay are not visible
from mobile devices.
If, however, you are referring to an ebay promotion of sorts, you cannot respond to those. Ebay
promo/adverts are always a 'one way' communication.
Or was it something else entirely?