UFUNCTION specifier Within=OuterClassName causes compile failure

I currenctly working on a something like uc state for my Character class.

UCLASS(DefaultToInstanced, EditInlineNew, CustomConstructor, Within=AGameCharacterBase)
class GAME_API UPawnStateBase: public UStateBase
{
//some code
}

Just like the UUTWeaponState in the UT project

But when I build the project there’s always an error:

Within class 'AGameCharacterBase' not found

I tried forward declaration, inculding more related headers, but the error remains still.

What do I miss?

Figured it out my self.

the Within specifier must be filled with FILENAME without extension, not the CLASSNAME that start with an A(for Actor) or U(for UOBject)

Hope this discovery could help the others someday

It certainly helped me. Thanks man!