This bug occurs when the imported character's appearance is from a Mass Effect (1) save. In this case, you will have to choose a default Shepard or create a new one.
Some faces cannot be imported into Mass Effect 3. You can also change your character’s Class. If you import a character you cannot choose its sex, BUT you CAN change his/her Appearance. If you import a Level 30 Shepard, you will have 1 point automatically placed for you in one Power, and 59 available to place at your whim.
