OK, let's dispense with the obvious. You cannot adapt a novel this lengthy into a two hour film without discarding huge amounts of material. Accepting that, adaptation becomes a question of judgment and craft. I'm sorry to say that both of those traits seem sorely lacking in this film. The previous 4 outings have all been fairly successful in creating logical plot flow, cause and effect relationships and maintaining at least some of the charm of the literary works they are based on. The current film is just a mess. Scenes from the book are simply hung together with no sense of one thing leading to another, vital information is rushed into the film only seconds before it is needed to explain further events and bad choices seem to have been made when good choices were available, using the same or less screen time.
Here are a few examples of what I mean, and this is by no means a complete list.
Harry's estrangement from Ron and Hermione, the emotional core of the first half of the book, is resolved by a scene in the film where he comes to them at breakfast and asks them if he can join them. This scene would have great emotional resonance if we had only seen, at some point prior to this, a scene of Harry not eating with them. As it is presented here, it is just a bit awkward. Those who have read the book can fill in the blanks but, presumably, this film is supposed to work for those who haven't read it as well.
In the book, The Weasley twins dramatic fireworks exit from Hogwarts serves the plot, diverting Umbridge so that Harry can contact Dumbledore. With that part of the plot removed, the scene only exists as an excuse for some effects shots. That screen time could have been used to much greater effect elsewhere.
In the book, the room of requirement appears to Neville, because he has need of a hiding place. That's the concept, the room appears to who needs it. There is internal logic. In the film, the room simply appears to him, with no rhyme or reason, as he is strolling by. The scene, as it appears in the book, would have taken no additional screen time and would have given the film better logical flow.
The absence of Hagrid is mentioned only briefly, with no sense of concern, at the beginning of the film and then completely dispensed of until nearly act 3, when it is suddenly announced "Hagrid is Back!" as if it should have been weighing on everyones mind. Well it won't weigh on anyones mind unless you impart it any significance earlier on. The fact that he, and his half brother are introduced only minutes before they are necessary to resolve the Umbridge plot line is just bad craft.
I could go on and on about this, but I'll let those examples stand for themselves. There was much that was good in this movie, in terms of performance, effects and design, which is why I am giving it a 6 rather than the 2 the screenplay deserves.
Here are a few examples of what I mean, and this is by no means a complete list.
Harry's estrangement from Ron and Hermione, the emotional core of the first half of the book, is resolved by a scene in the film where he comes to them at breakfast and asks them if he can join them. This scene would have great emotional resonance if we had only seen, at some point prior to this, a scene of Harry not eating with them. As it is presented here, it is just a bit awkward. Those who have read the book can fill in the blanks but, presumably, this film is supposed to work for those who haven't read it as well.
In the book, The Weasley twins dramatic fireworks exit from Hogwarts serves the plot, diverting Umbridge so that Harry can contact Dumbledore. With that part of the plot removed, the scene only exists as an excuse for some effects shots. That screen time could have been used to much greater effect elsewhere.
In the book, the room of requirement appears to Neville, because he has need of a hiding place. That's the concept, the room appears to who needs it. There is internal logic. In the film, the room simply appears to him, with no rhyme or reason, as he is strolling by. The scene, as it appears in the book, would have taken no additional screen time and would have given the film better logical flow.
The absence of Hagrid is mentioned only briefly, with no sense of concern, at the beginning of the film and then completely dispensed of until nearly act 3, when it is suddenly announced "Hagrid is Back!" as if it should have been weighing on everyones mind. Well it won't weigh on anyones mind unless you impart it any significance earlier on. The fact that he, and his half brother are introduced only minutes before they are necessary to resolve the Umbridge plot line is just bad craft.
I could go on and on about this, but I'll let those examples stand for themselves. There was much that was good in this movie, in terms of performance, effects and design, which is why I am giving it a 6 rather than the 2 the screenplay deserves.