Whether it's in school or at the office, you can’t always get along with everyone — and this also applies to celebrities.
Sometimes it's because of working differences. Sometimes actual arguments or on-set fights can cause a riff between stars. Other times, a celebrity’s alleged behavior, legal issues or political/worldviews might stop other stars from working with then. And while many of us can't always choose who we work with next, most celebrities do have a say in who they will collaborate or work with on future projects.
PopCrush 'Refusing To Work With...'. If always said that if people cannot separate own private life from own professional life, it could spell trouble...proves it...