Tree House of Horror X - S11-E4
Plot hole: In "Life's a Glitch", Lisa finds out that she has a seat on the spacecraft going to Mars as the proofreader. How, though, was she not informed of this before going to the rocket? The family only finds out about the rocket after finding Krusty's letter/invitation and the fact that she was on the list there would be no reason why she wouldn't have been informed of this. It was still New Year's Day so if it had been by mail then it would have to arrive before the New Year so as to make the plan work, being as it was a public holiday and no mail would be delivered. Therefore it would have to be delivered personally or someone would need to contact her. There were also many well known celebrities and figures ready to board the rocket. I can't imagine they were all home in time to gather their mail and were all somehow contacted, yet Lisa was simply walking around town and at church and they couldn't find her? There was also no evidence to suggest anything would have stopped her from either receiving the invitation in time or being informed of the mission.
Tree House of Horror X - S11-E4
Character mistake: When the Collector is putting Lucy Lawless into her plastic bag in his lair with the other celebrities, he refers to Tom Baker as "Doctor Who." As a sci-fi nerd, he would know the character's name is simply "The Doctor."
Tree House of Horror X - S11-E4
Continuity mistake: In "I Know What You Diddly-Iddly Did", Marge's necklace keeps changing from red to white when the Simpsons are at church, and when they go back home.
E-I-E-I-(Annoyed Grunt) - S11-E5
Plot hole: When the Simpsons run away from the duel, they go to Homer's childhood farmhouse. But Homer and Grandpa burned the farmhouse down in the episode "Grandpa vs. Sexual Inadequacy".
E-I-E-I-(Annoyed Grunt) - S11-E5
Revealing mistake: After Lisa says "For a product that's evil and deadly" while standing in front of the tomacco stand, there's a duplicate Lisa behind her that stands still while she moves, giving Lisa the appearance of having two heads. It looks like the animators made a mistake while trying to animate Lisa.
Hello Gutter, Hello Fadder - S11-E6
Continuity mistake: When Homer is talking to Ron Howard on the street, there is no pocket on Homer's shirt. But when he takes the money from Ron, he puts the money in a pocket that suddenly appears.
Continuity mistake: In the scene after Homer and Apu rescues the babies, Maggie is first seen wearing a bow. Then, when she's next seen, it's gone. When we see her one more time, the bow is back.
Continuity mistake: When Millhouse is being chased outside by a sun ray, the ray burns the pavement. It then turns around, and the pavement is now no longer burned. (00:01:40)
Continuity mistake: In the beginning, at the hospital, Maggie's bow changes from red to blue when Marge says "Why are you doing that?"
Continuity mistake: In the dinner scene at the end, Maggie is not wearing a bow, but when everyone tells Moe "Merry Christmas", she has her bow on.
Continuity mistake: During the revival meeting, Ruth Powers has a bandana on in some shots, and doesn't have it in other shots.
Continuity mistake: Homer was wearing a knit cap when the bucket fell on his head, but didn't have it when the bucket was removed. And since he was wearing a knit cap when the bucket fell on his head, his hair shouldn't have been ripped off when the bucket was removed.
Continuity mistake: When the doctor asks him if he has a moment and Mr.Burns looks at his watch but by the next scene it is gone.
Continuity mistake: At the beginning of the show, the hospital Mr. Burns is at has a sign in front of it that reads, "Got Tumor?", but when we see the hospital again it isn't there. Additionally, the "Mayo Clinic" sign atop the building gets noticeably smaller in the second shot.
Saddlesore Galactica - S11-E13
Continuity mistake: During the BTO concert, whenever the camera focuses on the crowd, the Simpson family is seen at The Front of the crowd. When the camera focuses on the stage, the Simpsons are at the very back of the crowd.
Alone Again Natura-Diddly - S11-E14
Continuity mistake: In the episode where Maude dies, Homer puts Ned to bed in the right hand side. When Ned tells Rachel he's ready to smooth out Maude's shape, they smooth out the right hand side.
Alone Again Natura-Diddly - S11-E14
Continuity mistake: Homer's watch disappears when he is getting his car fixed.
Alone Again Natura-Diddly - S11-E14
Continuity mistake: When Homer is filming Ned cutting the bushes between the two front yards, the camera Homer is holding suddenly switches eyes.
Missionary: Impossible - S11-E15
Continuity mistake: This mistake happens twice in the episode. At first, when Homer arrives on the island, he gives the islanders some bibles and says "Knock yourself out." Ack says that they cannot read. Yet later when Homer is revealing the casino, Ack reads "The Lucky Savage-?"
Suggested correction: Homer had been there for a while when the casino had finished construction. He could have taught Ack to read.
Missionary: Impossible - S11-E15
Continuity mistake: When Q'Toktok says "I told you we should have asked them", his hair is black instead of grey.
