The film didn't really work for me either.
It actually felt like two entirely different films that had been spliced together. And whilst each film could have worked in isolation, they didn't really gel together very well.
That's not to say you can't mix comedy and serious drama. But, for me at least, the comedy elements needed to have been a lot darker and understated to have worked. Parts of this film are genuinely quite harrowing, and you can't really say that about The Producers.