TP "Error attempting to sell"
It’s the spam/bot filter. It lets you list x amount of items before it shuts you down for 30 seconds before you can list the next item when it resets and blocks you again. It is kind of annoying, but it helps.
As Belial said, it’s the spam/bot filter. But apparently instead of making it say “Please wait 30 seconds before listing more items.” or something to let you know it’s a filter of some sort, it’s just left telling you there is an ERROR. That is what bugs me the most about it. :P
From my experience, you can put up around 10 items/minute. If you stay below this rate you won’t run into the problem.
It’s annoying because normal users regularly hit the cap.
If it’s a spam bot filter, it’s broken.
I tried to post a stack of 5 sharpening stones, got the “Error attempting to sell” thing, they disappeared from my pack, I got charged for the sale and they’re not listed on the “Item’s I’ve sold” list.
They were the only sale I’d attempted.