Steam app "CONFIRMATIONS" error?

Check if it's already listed and that's why you're getting an error.

Happened to me a couple days ago. It was fixed after ~3 hours though.

Steam Status · Is Steam Down?
https://steamstat.us/

There was about two hours of downtime. (Maintenance?)
Probably recovered?

I'm having it right now

+1 meow

I have the same problem

No one can confirm trades. Therefore, trading is in fact down.

"use our app that lets us better track, record and sell your data", says steam
-but I dont want to...
"you must", says steam
-...ugh fine. Done. So this will help me do trades and sell things on the market now?"
"lol no, denied", says steam.

https://steamcommunity.com/groups/tradingcards/discussions/2/3469477582938414488/?ctp=3
Also happened last week on Steam routine maintenance.
We couldn't confirm any of our trades/market listing, it was down for about 24hrs.