My first suggestion would be that your brother try to use the "Verify integrity of game files" option on Steam. If that doesn't help, we'll need his player.log and diagnostics files to try figure out what's wrong.

QuirkyCarlos wrote:

Hello I’ve just bought the definitive edition which includes all the dlcs from steam but I don’t have access to the frozen fangs dlc it’s the only one I don’t have hoping a dev or someone from the team can help I’m happy to provide evidence as proof 

Hey, would you mind checking it now (ingame)? The issue should be solved and Frozen Fangs should be included in the base game.

We're already looking into it and we think we know how to fix it, but I don't have any guess when the fix will be ready.

Yes, we've confirmed that there are indeed problems accessing Frozen Fangs, and have identified some potential causes. We're working on resolving the problem.

There was a limited number of keys for this giveaway. Unfortunately, the supply ran out an an inopportune time, which led to a delay in putting up the out-of-stock message. We're sorry you missed the opportunity to claim the game.

Hey,

thanks for the report. We've been looking into this, but some additional information would help us. Could you tell us about the following:

We are investigating the issue. In the meantime, the game is set to install to your OS drive, as that seems to prevent the issue.

The free trial was a limited time offer last week. It's unfortunately not available anymore.

When I'm making a request to Steam api, I don't see Endless Legend in your library. When did you buy it?

Hello PsyFusion,

Do you still have the error? Servers might have been overwhelmed when you try to redeem the Guardians DLC.

Besides, which version on Endless Legend do you have? You won't be able to redeem the reward if you only have the Free To Play version of Endless Legend :)