Everyone's entitled to make a few stinky movies in his or her career, and we always forgive our favorites because everyone does it. Either they're stuck in a contract, or they had momentary bad taste but every actor and actress has stinky movies listed on their resumes. Even Errol Flynn.
The Green Light started out to be an interesting film. Errol, a dedicated doctor, makes a judgment call to operate on a patient, even though the main surgeon wasn't present. Halfway through the operation, a senior doctor shows up and takes over. The patient dies, and Errol willingly take the fall for it.
I assumed the rest of the movie would be about him trying to clear his name and get reinstated in the hospital. Unfortunately, his character had other plans. The title refers to a sermon delivered by Sir Cedric Hardwicke in the film, and as Errol's character was previously shown to not be a very religious person, it's pretty obvious what direction the movie plans to take. This isn't a hospital movie, it's a religious movie, so keep that in mind if you decide to rent it. Even if you usually like those movies, this one doesn't seem like it was thought out very well.