Just because you’re a hit on YouTube doesn’t mean you should be making movies. Case in point: the three likeable NYU grads who perform Internet sketches as Derrick Comedy. Two or three minutes is fine, but 105 minutes is excruciating. Riffing on the Hardy Boys and Encyclopedia Brown, the trio of Donald Glover, D.C. Pierson, and Dominic Dierkes play overgrown boy detectives now shunned by their high-school classmates. For good reason: The three überdorky 18-year-old virgins are oblivious to girls (“Yuck!”), an embarrassment to their parents, and weak on their powers of deduction. That a rash of murders should break out at the lumber mill provides them with the opportunity to visit a strip club, score some coke, and drink dog urine (don’t ask), all less funny than it sounds. The forced Napoleon Dynamite naivete was already tired by that movie’s 90th minute, and Mystery Team feels more than six years past its sell-by date. A late-film appearance by the always-reliable Matt Walsh (The Hangover, Upright Citizens Brigade) confirms the movie’s core problem: It’s more fun to watch adults knowingly misbehave than innocents unwittingly bungle.