Clicking "Respond Now" on eBay non-receipt email doesn't work

[sardonicus001]

I received a complaint through eBay from a buyers who said his purchase hadn't arrived. eBay gave me three days to respond, however when I click on the Respond Now button my account opens and I get a message saying "Oops, we had a technical hiccup". I tried a different method of responding, going into the Resolution Centre and clicking on Take action next to the complaint details. This time I got a message saying "We are unable to process your request". I tried both these procedures last night and this morning with the same result. I am rather concerned as I would like to ask the buyer to allow another week or so for the article to arrive. If I cannot responf within three days eBay will take matters into its own hands. Help!