It Caused a Rift Between Robin Williams and Disney
Robin Williams had a falling out with Disney over 'Aladdin.' He worked for scale on the film, partly out of gratitude for the studio making him a film star in 'Good Morning, Vietnam,' and partly in exchange for the studio downplaying his role in the film during promotion so that Williams could promote his upcoming movie 'Toys.' Disney complied on some fronts, but ignored the deal on others. (For instance, Williams was heavily featured in the film's promotion.)
Williams declined to voice the Genie in many subsequent projects and was replaced by Dan Castellaneta, best known as the voice of Homer Simpson. Disney and Williams eventually reconciled and Williams has since been named a Disney Legend.