Having Trouble Using Fortnite's assets in UEFN creative

Hello, I’m trying to create a boss fight in UEFN using an in game character from fortnite. But every time I load the asset, this validation error occurs. Just trying to understand why it would be doing this if its a fortnite asset you can use in other manners but not in this way?

In what way are you ‘loading the asset’? Verse code? Can we see?