Complex sentence: On September 11,2015, Katt Williams joined the cast, on September 17,2015, Glenn Close was in final negotiations to join the film, and on October 7,2015, Katie Aselton was also in final talks to sign on.
Split into simpler sentences: On September 11,2015, Katt Williams joined the cast of the film. On October 7,2015, Katie Aselton was also in final talks to sign on.