Board Game Arena

Do I not have all the resources for the 4th wonder? There's enough stone plus the papyrus from the west trading post. Even not counting the west trading post, one of my neighbors had a papyrus and I had 17 coins. What am I missing?

only if 1 of your neighbours has the Papyrus (Paper) and you have 1 coin to buy it.

maybe your neighbour's Papyrus was not the sharing kind. If it was on a yellow card then it is not shared to neighbours.

you have a link to the game table?

What you are missing is the screenshot that shows your left and right neighbors so we could see if they have the Press/Papyrus for trade. Without the screenshot, we would just be guessing why you couldn't build your 4th wonder. So, after giving up trying to find your game table, here is my guess:

There was no Papyrus available from your neighbors. It's unlikely that you did not have enough coins to buy a papyrus because you had Marketplace (so Papyrus would have costed only 1 coin, and you say you had 17 coins or about 8 coins before you built Arena). Your Craftsman's Guild scored only 2 points, meaning there was only one gray/manufactured good card among your neighbors. So, which gray card was that? Well, you built two 6-point blue cards, available only in the third Age, and they are Senate (does not require any Gray card) and Town Hall (requiring a Glass, no free chain). So, the one Gray card that your neighbor had must have been Glasswork (Glass). So no Press/Papyrus.

Most likely, the Papyrus you saw was not from the gray/Press card but from a Forum (yellow card), which cannot be bought by other players.