Lifeforce (1985)

Continuity mistake: In the beginning, when the two shuttles have docked together, one of the NASA astronauts inserts some kind of key into the door and begins to turn it. When he does you hear a ratcheting sound, however, once the door begins to open and there's a shot from the inside of the uninhabited shuttle, the astronaut isn't holding any type of tool, and still the ratcheting sound can be heard as the door opens further.

Revealing mistake: During the scene on the helicopter when the female vampire is developing from the entrails of blood from the two dead men onboard, it is obvious that they are mannequins/dummies as the blood leaves them.

Space Girl: I am the feminine in your mind, Carlsen.

Colonel Colin Caine: Colonel, take it from the beginning. Assume we know nothing... which is understating the matter.

Dr. Hans Fallada: It was two hours ago that the guard was attacked. I wouldn't be at all surprised if we're seeing a pattern here.