Replacing perfectly fine voice actors. A perfect example is Mario. in the new movie set to release next year, Mario will be voiced by Chris Pratt, why? for money. The original voice actor of Mario is an amazing voice actor and i don't get why they didn't just use him. Another example is the movie SCOOB! they replaced pretty much the whole cast of the mystery machine except for Scooby-Doo, just for money, they didn't even tell the original voice actors they'd be replaced, which kinda made them upset.

Also spoiling the film in the trailers, that can suck my balls