At first, AMC's The Walking Dead had Frank Darabont's fingerprints all over it, both stylistically and with his pick of original cast members (Melissa McBride, Laurie Holden, and Jeffrey DuMunn, in particular, had worked with him before). In an surprising network decision, though, Darabont was booted from the second season, despite its early ratings success.
AMC, which was fielding financial issues with the creators on Mad Men and Breaking Bad at the time, decided to slash its production budget on The Walking Dead and oust Darabont over creative and managerial differences. Glen Mazzara, who was Darabont's second in command for the show before being promoted to chief, said the split came from a mix of friction between Darabont and Kirkman, the network's inflexibility over prep time for the second season's premiere, and Darabont's strength as a filmmaker and not a showrunner that led to the split. Darabont is understandably not one of the millions of current viewers, and DeMunn followed him out.
After being let go, Darabont pursued legal action against AMC, testifying in a deposition that the network created "crisis-level problems" by slashing the show's budget in spite of ratings success and accusing executives of essentially inventing reasons to fire him. In late September of 2016, Darabont's lawyers revealed they were seeking more than $280 million in damages, a figure reflecting their case's contention that AMC deprived Darabont of revenue by artificially lowering the show's license fee. According to the judge presiding over the case, it's unlikely to see trial before 2018—leaving plenty of time for further accusations between Darabont and his former bosses.