From the time we first see Carrie in her "best man" outfit to the time she and Big arrive at the wedding, Carrie's hairstyle changes. It is not slicked back and she does not have a braid. Perhaps we are meant to think she changed it, maybe opting for a simpler style (something easier to redo) after she and Big spent the hour in bed, but it is not addressed in the film.
When Carrie has her meaningful discussion with John in their apartment, she sits down in a chair and crosses her left leg over the right one. Uncrossing her legs, she throws a cushion onto an opposite chair. In the wide shot that follows, her legs are still crossed.
When the ladies arrive in Abu Dhabi Airport, their bags are tagged JFK for New York's John F. Kennedy Airport, where they're departing from. The bags should be tagged for their final destination AUH, for Abu Dhabi.
Charlotte says she used her maiden name of York on her passport instead of her married name of Goldenblatt, implying that a Jewish name would be poorly received. She would not be able to change the name on her passport without legal documentation of a name change.
While flying to the UAE, Carrie, during an internal monologue or narration, stated that they were flying over Africa. If a flight left New York for Asia, it would not take a route over Africa. It would likely fly closer to the North Pole because the circumference of the earth is smaller near the poles than near the equator.
The goof item below may give away important plot points.
The internal chronology for the film is all over the map. The girls don't hold off on booking their trip to Abu Dhabi because they said if they waited a month, they'd "burn up." But the clock by Carrie's bedside in the hotel says "Aug 26," which would be right in the middle (or rather toward the end of) the hottest time of the year. Additionally, Miranda had just quit her job so she could go to Brady's science fair presentation at school. Even if it were a few weeks before, Brady wouldn't be in school in the summer. When the girls returned from Abu Dhabi, Samantha and Rikard celebrate the Fourth of July together.