Plot hole: Gary Winkle appears as the supposed fourth guy from Winterfest, in the first film. He is shown later in this film in the alternate future, and appears to be around the same age as before. Meanwhile, all of the main characters are much older, and Adam's son is already an adult by now. (00:03:00 - 00:41:00)
Continuity mistake: Jacob gets a call on his ear phone with a news report of Lougle going up on the market. It cuts to the other side as Lou is about to slap the hologram away and suddenly the logo for Lougle is replaced by a sign that says U-Street and has a large 95 under it. (00:31:25)
Plot hole: They have to invent Nitrotrinadium when they travel to the future because it was not invented yet, but was in the Russian drink in 2010, so should have already been available when they travel to the future.