Plot hole: Jim leaves to attend his family Christmas as evident by his dialogue in the opening scene, and evidently Carl is supposed to be at home to his family in the morning as well, but both are killed by Thomas. When the movie ends with Angela entering the city, it is early morning just before sunrise. Jim and Carl's families would have noted that they were not home on time, and therefore would have had someone searching for them. This makes it implausible that Angela's situation would not have been discovered.
Plot hole: In the yearbook scene Tim barges into Jamie's room and asks her to sign his yearbook, pushes Chris off the bed, and they somehow get their yearbooks mixed up. Tim's yearbook is left in the room with Jamie and Chris, while Tim takes Jamie's yearbook that Chris wrote in with him. When Chris asks Jamie to read the message he wrote in her yearbook, she instead reads the message that Tim wrote to her in his own yearbook. If Tim was asking Jamie to sign his yearbook, why would sign the yearbook with as if he was signing Jamie's. If he was intending to sign Jamie's yearbook, he would have written in the same yearbook that Chris wrote in and not his own.
Plot hole: When cousin Eddie kidnaps Mr. Shirley, Shirley's wife immediately calls the police. She describes Eddie as 'brutish and huge' or something similar, and wearing a 'blue leisure suit'. She also mentions that she got the license plate number of the vehicle. But how did the SWAT Team know to go to the Griswold's house to find Mr. Shirley? Eddie's RV is not registered in the Griswold's name so the plate numbers would not be much help in finding the culprit.
Plot hole: Near the end of the film it's revealed that Drew grew up poor with only his mother, who had to work double shifts to survive. So how did they afford that huge house? Even the Valcos are supposed to be struggling financially yet they now live in this massive house too.
Plot hole: It's never explained how Ms. Pearly the landlord knew Craig and Day Day since they were kids, and it also doesn't make much sense how Craig and Day Day are so scared of Damon and can correctly recall him being this super buff grown adult, when he was locked up for 12 years and their characters are all in their early 20s.
Plot hole: Lots of police officers saw Santa flying at the end. This should've caused the world to accept Santa was real.
Suggested correction: From ONE location? Also, people wouldn't believe in Santa that easily.
Suggested correction: It should also be noted there were no cameras to capture the event, and not many eyewitnesses. Only a few neighbours and some officers. Even if these folks now believe in Santa, who's going to believe them? Folks they tell are going to think these folks are making it up, that their brain or someone else played a trick on them, or that they are mentally disturbed.