My Steam code was already activated?

I’m sure I’m the idiot here but when i go to activate the steam code for MCC Season 7 - Steam it says I am trying to enter a duplicate product code. Anyone else encounter this? TIA

The flight for Season 7 ended weeks ago so any and all codes no longer work.

The flight ended a few weeks back and with it all game builds/keys were revoked; those are just generic messages you’ll receive when a key has expired.
You’ll have to wait for the next flight I’m afraid.

Closing per the above ^