Sometimes when I am on the page to claim a game, I see something that looks really cool. However, whenever I try to add the game to my collection, I get an error. For example:

This has been happening for months, and it's really frustrating. I've tried to turn off the ad blocker to see if that's what was causing it, but unfortunately that didn't work.

Edit 07/14/2021: The issue was fixed for a bit, but now whenever I attempt to add a game to a collection, it says "Invalid game"