Factual error: One of the deaths involves a burning candle, a car and a leaking fuel tank, resulting in an explosion. This wouldn't happen. Multiple independent test evidence that petrol/gasoline can't be ignited this way, a flame isn't hot enough. Only the fumes can be ignited, which isn't what happens here, and the tank wouldn't explode anyway.
Happy Death Day (2017)
1 factual error - chronological order
Directed by: Christopher Landon
Starring: Israel Broussard, Jessica Rothe, Ruby Modine, Charles Aitken, Rachel Matthews
Continuity mistake: On the third and fourth day, Carter's roommate shows up earlier than the first 2 days. And Tree's suspect tips notebook every day don't reset and the line and erases are the same.
Tree Gelbman: I can't change what I've done, but I can start trying to be a better person today.
Trivia: The plot of the movie is similar to Groundhog Day which is something that Carter mentions to Tree at the end of the movie. Tree's roommate's name is Laurie Spengler, which is a reference to Egon Spengler, played by Harold Ramis in Ghostbusters. Harold Ramis co-wrote and directed Groundhog Day.