Continuity mistake: When Kaley put her hand through the waterfall, she is on the right side. In the shots both before and after, however, she is on the left.
Continuity mistake: In the beginning, Sir Lionel leaves for Camelot in what looks like spring or summer. Camelot is 3 days ride, and Sir Lionel gets killed on the day he arrived. Three days travel back (totalling 6-7 days) and it shows the dead of winter.
Plot hole: Throughout the movie, Bladebeak works for the villains. But, during the climax, he becomes a good guy without any explanation.