"Last answer by..." is empty

Hi, sorry to hit you with another issue so quickly. If you go to the forum index:
simracer.club/foros

You'll see that the last answer by does not have the user show up. I assume the avatar, name and/or link would go in this space.

It shows as "Última respuesta por [blank]". I assume some kind of user data should be where I have indicated the [blank]?

Thanks!