Other mistake: After realising they can track the mother box, Batman says they have to go back to his base to use one of his satellites to track it, and they all do so. Which completely ignores the fact that Cyborg could easily access the satellite feed directly using his abilities and display it to the others on any nearby screen in Star Labs.
Plot hole: WW mentions that "As Darkseid waged war on Earth, he found a secret there", that being the Anti-life equation. But later on it turns out that after being defeated, planet Earth is so "anonymous among a trillion worlds" that he never manages to find it again and destroys another 100,000 worlds (his words!) to look for it again. That would mean that they lack any sort of navigation, and it's hardly possible anyway that the planet would be "anonymous" when it contains what Darkseid wants the most.
Factual error: In Part Two, as Diana explains to Bruce Wayne the history of the Mother Boxes on Earth, we see an extended flashback of Earthly gods and warriors in epic battle against Darkseid. When Diana says, "A golden age of heroes fighting together," we see a closeup of an Amazon archer drawing back an arrow right-handed, leaning right, and releasing it. However, the arrow is UNSUPPORTED on the bow, so she couldn't possibly aim or control the arrow. A truly amateur mistake. (01:03:59)
Plot hole: The heroes find Steppenwolf's base thanks to Cyborg's dad, who superheated the core of a Mother Box so it shows up on a thermal scanner. But the box itself wasn't emitting any heat on the outside, and a satellite can't magically infer the internal heat of an object if it's not conveyed to the surface. If Wayne has such precise satellite sensors, it would also spot a nuclear plant suddenly drained from radiation, and the intense energy (and heat) caused by Steppenwolf's activities.
Other mistake: In this version, Queen Hippolyta whispers "Return to me, Diana" as she shoots the arrow, as opposed to "Listen to me, Diana" in Whedon's version. Whedon's line made sense, since it was a warning, this does not, since Diana never comes back to Themyscira nor she is supposed to, being busy thwarting the invasion in the Land of Men. There's no reason why the Queen would say that line. (00:43:10)
Stupidity: In this version, Flash does not carry the hostages to safety; he is sort of a cheerleader/crossing guard appearing in different spots of the stairs asking if they are OK and saying "This way." What sort of role in a battle is that? How does that help in any way? It's not that he's afraid of battle like in Whedon's version and he fights nobody on the path. (01:58:25)