Continuity mistake: When Finn retrieves the jacket from the downed TIE fighter he's standing right in front of it, but when it starts to sink he takes a couple of steps back, then the long shot shows him further away, and even further when it explodes. (00:24:40)
Factual error: In the opening sequence, the camera pans down on a planet and moon that are three-quarters lit in sunlight (with the sun being far off-camera to the left). A battlecruiser then crosses the images as a silhouette, eclipsing the planet and moon in total blackness. Impossible. The battlecruiser should have been lit three-quarters in sunlight, same as the planet and the moon. Stranger yet, as the stormtrooper shuttles are deployed and cross over the battlecruiser silhouette, the shuttles are illuminated. (00:01:55)
Other mistake: When Finn and Rey see Han talking to Ben on the bridge, they look directly down. But the platform they're standing on is to the right of the bridge. If they're looking directly down, they would be looking at either the floor or the chasm around the bridge. They should be looking to their left.
Continuity mistake: In the scene on the bridge when Kylo Ren kills Han Solo, if you look carefully at Kylo's lightsaber during the series of shots immediately before he ignites it, you'll see that the saber is pointed completely the wrong direction - if Kylo ignited the saber the way it's pointed in those shots, the blade would come out perpendicular to the direction it would need to come out to kill Han. Then Kylo ignites the lightsaber, and suddenly it's pointed the right way, even though he never rotated it. And yes, Kylo's lightsaber is a crossguard, but it's the main blade that kills Han, so this is definitely a mistake.
Continuity mistake: When the falcon is caught in the tractor beam, in the shot after Finn says "it's the First Order," the shot cuts to Rey saying "What do we do? There must be something." There is a strand of hair on the right side of her head, and as the shot ends, the tip of the strand is pointing away downwards. In the next shot, the tip of the strand is suddenly curled up and closer to her neck. (00:39:35)
Continuity mistake: When we first meet Rey, she is scavenging Imperial wreckage, and she slides down the sand dune on a makeshift sled (she left her speeder at the base of the sand dune, which means she trudged up that massive dune). When she reaches the bottom of the dune, her speeder is casting a distinct, dark shadow on the sand. As she fires it up and rides away, the speeder suddenly casts no distinct shadow on the sand, even after she reaches her destination and parks it. (00:12:00)
Continuity mistake: When Han is holding Leia to his chest a close-up of her face shows his hand holding her head with his fingers near her ear. The shot changes to behind her and his same hand has instantly moved to the base of her neck. (01:34:50)
Continuity mistake: When Rey is unloading her speeder bike the sun is setting, but when she goes to trade her gear it's bright and sunny, and when she goes home, in the long shot on her speeder bike the sun's setting again. (00:12:45)
Continuity mistake: When Rey first meets BB-8 there are many footprints in the sand going towards it. When they walk back to the fallen AT-AT, the distance is far greater and Rey's footprints have disappeared. (00:15:10 - 00:16:30)
Continuity mistake: When Rey is fixing BB8's bent antenna, at first, the antenna is shown as thin and flexible. But as the scene changes between Rey and BB8, the thin antenna changes to a thicker and slightly more rigid antenna being held between her fingers, then back to a thinner one. (00:15:53)
Continuity mistake: When Rey is giving the scrap piece to Unkar Plutt, in the wide shot where Unkar says "What you brought me today is worth...", Unkar is holding the scrap piece upwards. The shot changes to a closer shot of the two and suddenly Unkar is holding it sideways. (00:13:20)
Continuity mistake: After Rey has fixed BB-8's antenna, she tells him the Niima Outpost is that way, pointing towards the outpost with her left arm. She holds onto the back of BB-8's antenna with her right hand and begins taking her hand off him. The shot cuts to a shot of BB-8 and Rey's right hand is suddenly off BB-8 entirely, down by her side. (00:15:55)
Continuity mistake: When the rathtars begin attacking, in a shot of Han looking down the corridor, one of the Kanjiklub members is running through a doorway whilst running from the rathtar. The camera cuts to a closer shot of them running from the rathtar, and the same Kanjiklub member can be seen running through the doorway a second time. (00:46:00)
Continuity mistake: When Maz Kanata shows Finn, Han and Chewie the lightsaber, watch the blaster strap on Finn's shoulder. When Maz is saying "Take it. Find your friend," the strap is shown on his shoulder. Finn then takes the lightsaber and the strap is suddenly closer to his neck. Then a couple of shots after, the strap is suddenly back to its original position again. (01:12:00)
Continuity mistake: When Finn, Rey, Han and Chewie are headed towards the oscillator, they stop running, seeing the battle between the Resistance and the First Order and Han says "They're in trouble. We can't leave." At this moment, the camera is behind the group and Han is standing next to Finn on Finn's right. The shot then cuts with the camera in front of them, and Han is suddenly standing in front of Finn. The camera cuts again and Han is now standing on Finn's left. (01:42:35)
Continuity mistake: When Kylo Ren is trying to read Rey's mind, there is a closeup of Rey saying "Get out of my head!" During this shot, there are tear streaks running down her face. In the rest of the scene, these tear streaks are gone. (01:27:40)
Answer: The First Order already has the piece that R2-D2 was carrying as well. That is the first piece, the large piece of the map missing a small section. The second piece is carried by BB-8 and only by BB-8, the missing piece in the map. All the first order needs is that second piece, and so does the Resistance. However the Resistance needs R2-D2 to activate again so he can show them the first piece, so they can put the second piece in it.
lionhead