This is Relativity Studios' first release since filing for Chapter 11 Bankruptcy Protection on July 30, 2015 after lawsuits and missing loan payments. In March 2016, Relativity emerged from the bankruptcy. "The Disappointments Room" was finally released on September 9, 2016 under Relativity's Rogue label.
The trivia items below may give away important plot points.
There is a scene missing on the DVD release and all the iTunes and digital releases that was present during the theatrical release, the scene that is nowhere to be found is the dinner table scene where Dana freaks out. This results in 5 minutes being removed from the final cut.
A lot of footage was left on the cutting room floor during post-production. This includes a party scene Mr. and Mrs. Black were throwing and underneath was The disappointments room that overlooked the garden (The garden they show all overgrown with the broken statue, now beautiful and pristine in the flashback) where the elegant party was being thrown. Fancy food, drinks, candles lit, an opera singer in the garden, party goers dressed up in their 19th century style ball gowns, men with beards laughing and pipe smoking, and so on. Dana walks through this party in disbelief of what she's seeing and looking for Lucas. This scene was alluding to the parents having this amazing party all the while their disappointment child is upstairs being hidden away from society, which would have added to the unfolding of Dana finding out about the child's story of abuse, sparking her curiosity to go see that woman who knows all about the history of disappointment rooms. Another important scene that was edited out has to do with the German shepherd scene where the cat is killed, and Dana has a vision of her son being attacked by the dog. All of that was leading up to the fact that Mrs. Black was attacked and killed by her husband's dog and her husband did nothing to stop it from happening. The scene in the theatrical cut instead merely features the dead cat completely out of nowhere making it pointless.