Why has my Team Fortress 2 inventory vanished and then reappeared on Steam?

Question

I want to sell some tf2 items on the Steam Market, however, my inventory seems to have vanished, that is, the tf2 tab is no longer there. After I noticed this, I decided to try selling through the tf2 backpack itself, both to make sure that I hadn't actually lost my items and to see if I could actually sell them. I did have my items, but when I select the "sell on Market" option, it just sends me to the first item in my Steam inventory.

This was the situation as I began writing this question. In order to write it as accurately as possible, I performed my actions in tf2 again, only to discover that it is now working. I then went to my inventory on Steam and (after refreshing the page) the tf2 tab is now there again. What could have caused the tab to vanish and then reappear?

Answer 1

The servers on Valve's end that are used for backpack information and/or trading occasionally go down or are under heavy load. When this happens, TF2 and Steam cannot access your backpack at all.

If this happens, it's likely that your items may be currently untradable and/or your entire backpack will be completely inaccessible, meaning you'll be unable to trade, and - if you're playing - your class loadouts will revert to using the stock loadouts for a period of time.

Whilst there is no guarantee what time they may come back up, you can also check on TF2Lists for the current status of the servers. If they are currently down, your options are limited. You can try:

1. Waiting a while (anything from 30 minutes to a few hours) and attempting to play/trade at a later time
2. Praying to Gaben for deliverance*

_{* I cannot vouch for the reliability of this method}