Im still getting it the same issue, I can catch fish in pools but anywhere else just empty loot window every time. Really annoying as I was tryna level cooking and needed just a few carp, and had to travel to shrine to buy more instead of just fishing them up. maybe at 500+ skill it would be different. I’m assuming it is a bug that is affecting people below 500 skill. According to a comment on wowhead around patch 5.3 in original mop that had made it to where you could not fail at catching a fish in pandaria which would result in anyone under skill level for pandaria to catch golden carp.