I had Killing Floor 3day guess pass, now I can't join giveaway Killing Floor

Sync Account? Or is the game still showing up in your library?

I am not sure but I heard you must wait 2 weeks.

Not much you can do, really, besides waiting.
Some say only syncing on tuesdays help, but I have no sources for that.

I had it from last Friday to Sunday, now it isnt in my library.

try syncing your account.

This is a known issue with free weekends and guest passes. All that can be done is for the user to remove any game content they may have on their computer and resync their SteamGifts account. It can take up to two weeks for Steam to update the user's library to reflect they do not own the game, however. Sadly, this is a problem on Steam's end and we can't change it.

I synced my acc. Killing Floor is there :-( . I'll wait 2 weeks than I delete games, how bobofat says. Ty for your time.

Should have bought it for a few dollars two weeks ago. :p