Udisha
Judy Garland (Valley of the Dolls, 1967)
The film, directed by Mark Robson had begun production and Judy Garland was set to play Broadway legend Helen Lawson but had to be fired after alleged issues of substance abuse. Helen was finally played by Susan Hayward.
Eric Stoltz (Back to the Future, 1985)
Back to the Future director Robert Zemeckis replaced Eric Stoltz after filming with him for more than a month. He felt the actor lacked the comedic requirement for Marty McFly and was replaced by Michael J. Fox.
Stuart Townsend (The Lord of the Rings: The Fellowship of the Ring, 2001)
After Stuart Townsend trained for Aragorn's role for months, director Peter Jackson felt that the character should be older to perfectly fit the description and took Viggo Mortensen instead.
Ryan Gosling (The Lovely Bones, 2009)
Ryan Gosling was replaced by Mark Wahlberg for the role of Jack Salmon. Ryan had even gained significant weight for the character but the director, Peter Jackson was not satisfied and fired him.
Megan Fox (Transformers: Dark of the Moon, 2011)
Megan Fox made some controversial comments and compared the movie filmmaker, Michael Bay to Hitler. Consequently, Rosie Huntington-Whiteley was taken in her place as Carly Spencer.