The Real Ghostbusters (1986)

Transylvanian Homesick Blues - S2-E65

Character mistake: Ray says that it's the very first time they've dealt with vampires. In Season 2 Episode 25, "No One Comes to Lupusville", the Ghostbusters had to deal with both werewolves and vampires.

Peter Venkman (I): It's times like this that I wish I'd listened to what my dad used to tell me.
Winston Zeddemore (I): Yeah? What was that?
Peter Venkman (I): I don't know. I never listened.

Show generally

Question: Excluding Maurice LaMarche, why were the voice actors for Ray, Winston, Peter, and Janine replaced in later seasons?