my halo mcc halo 2 flight steam key dosnt work

Does it appear an error code?

Have you tried to contact Steam support?

So sorry to hear this gamer.

Where did you buy the key from?

Perhaps contact the seller

May i know if you already done all this?

Step 1: Make sure you’re signed up to the Halo Insider program

Step 2: Ensure you have the entitlement to Halo Infinite (Campaign). (i.e. you have purchased it or have an active Xbox Game Pass subscription)

Step 3: If you’re participating on Xbox, have the Xbox Insider app downloaded, and opt into the Network Co-Op flight program once the flight is live. If you’re playing on Steam, you’ll be sent a unique key via Halo Insider communications to download the flighting build.

Step 4: Launch the build, party up with friends, and jump into Zeta Halo!

By the way, did you already received the invitation?

You’re going to receive like a redeemable key once you’re invited to test the co-op insider.

According to this official Halo thread:
“ Flights are their own separate builds from the retail game, meaning they are their own separate download. The flight should be smaller than the main game, but you’ll still have to download. So if you’re out of storage, clear some. Then of course you’ll have to wait during the download time too.

So, when you get access to a flight you redeem the code like you would with steam-keys. The flight will pop up like a new game. It should say “Halo Infinite - Insider” That’s how they did it before launch and for MCC. Since this is co-op, they might do what they did before and send extra codes to you so you can send it to friends.”

Source: https://forums.halowaypoint.com/c/community/hal...

If you didn’t receive the invitation yet and you’re installing the already existing Halo Infinite - Insider from your owned library, that’s the issue.

Microsoft Flight was put through Steam. It's not impossible for Halo 3 on PC to be on Steam.

Halo: MCC, Halo 5, and Overcooked 2 are my top 3!