My understanding is that they almost re-cast Simba. Apparently, he kept coming in hung over and strung out on catnip with no idea what his lines were. Disney asked Robert Downey Jr to come in and talk with him, and he explained about what Simba meant to all kinds of people, and how much this was going to change his life - because now, he had fans looking up to him, the person, not just Simba the character.
Long story short- other than that one time (I’m sure you saw the Entertainment Weekly photoshoot… and the National Enquirer) he’s been sober since… they were able to pick up his scenes and the shooting went off mostly without a hitch…
(/Sarcasm)
