The Conjuring 2 goofs

(at around 30 mins) While Janet is off school ill, after she ends a call from her mum who had rung to see how she was, she uses the remote to switch back to the channel she’d been watching, and the first channel she lands on shows an adult Jon Bon Jovi performing mid-song. Since the story is set in 1977, Jon Bon Jovi would have been only about 14 or 15 years old — roughly six years before he was discovered.

(at approximately 44 minutes in) While Lorraine is annotating the Bible, Kitty Kelley's biography of Nancy Reagan is visible on the bookcase. That book was not written until 1991.

(around the 10-minute mark) The scenes outside the school are set in the present day. The school sign displays an 11‑digit telephone number beginning with an area code of 012. At the time in which the film is set, London numbers used the 01 prefix, which was introduced in 1959.

The white Ford Cortina estate’s number plate reads HN08EHX, which would suggest it was first registered in the first six months of 2008, despite the film being set in 1977.

(at around 36 minutes) In the corridor scene after Janet ties herself to the bed and wakes to banging at the door, she opens it and calls out into the corridor. The next shot shows a bookcase with board games, and the game Bonkers is clearly visible — a title that was not released until 1978, a year after the film is set.

(at around 1h 2 mins) From the late 1960s, Marylebone station's covered cabway displayed large black-on-white British Rail signs proclaiming "Marylebone", complete with the British Rail logo in red, which were mounted spanning the road at either end of the roof. They remained in place until the privatisation of British Rail in the mid-1990s. Yet they are missing in this film, which is set in 1977.

The thickness of the wall between the front door and the bay windows varies between shots. In the on-location footage the wall is approximately five times narrower than in the studio footage. This discrepancy is evident throughout the film and is emphasised by the positioning of the ageing leather armchair and the width of the corridor.

(at approximately 1 hour 35 minutes) When Ed goes to fetch Janet from the cupboard, he burns his left forearm on a hot pipe. After he finally gets her out and collapses to the floor, the burn mark isn’t present, yet it reappears in a later scene.

(at about 1 hour 50 minutes) When Vic Nottingham turns up to chop through the door, hatchet marks are already apparent on it.

(at approximately 1 hour 4 minutes) When we first glimpse the doorknobs on the door of the girls' bedroom, they appear very old and painted. Later, after the door has been chained shut, the knob is a newer one with a brushed copper finish. The knobs are only of moderate strength and can be snapped off by a sharp strike with the heel of the hand from a man of Patrick Wilson's build.

The American investigators are shown arriving in London (and almost departing from London) at Marylebone station. In 1977 that station provided only a handful of regional services to Buckinghamshire and Oxfordshire, and certainly did not serve either of London's two transatlantic airports. At that time, trains to and from Heathrow were provided exclusively by the London Underground on a then-new extension of the Piccadilly Line, while services to and from Gatwick ran (and still run today) to and from Victoria station.

(at around 1h 35 mins) The sound engineer sent by the polytechnic is recording various ambient noises around the house and aims his microphone at an open door leading to the garden. The mic picks up crickets chirping — something highly unlikely for North London in late December.

Cellars like the one depicted were rare in 1970s England. Had the property possessed a cellar, the stairs would not have been constructed or positioned as they are shown in the film. The cellar is clearly modelled on an American design—large and spacious—rather than the dark, damp and relatively small cellars typical of London properties in 1970s Britain. Those that weren't converted were often filled with concrete because of flooding from the numerous subterranean rivers and sewers beneath the capital.

When Ed Warren picks up the guitar — implied to have been unused for some time — he neither needs to nor even attempts to tune it.

The fireplaces in the house are not typical of a 1930s British house; their proportions are wrong — they follow more American dimensions. You wouldn't come across a tiled fireplace like that in Britain.

Whilst Ed and Grosse walk over to their car, the remainder of the foreground in the film's 1970s depiction of England features a couple of recent-model cars driving past.

(Around the 43-minute mark) Back at home, Lorraine stands before a bookcase. Large letters are labelling the different sections of the small collection, but instead of A, B, C and so on, the letters spell out the demon's name. While this does reveal the name, there is no reason to think Lorraine would have noticed it earlier, as it can so easily be overlooked.

The layout of the house is quite unusual for a UK property of this age. At the top of the stairs is the bathroom, with a bedroom at the back. The front of the house features a small bedroom above the stairs and a larger bedroom to its right. Additionally, the rooms are far too large for the style of house shown at the beginning of the film.

(at around 1h 18 mins) When Janet appears to be suspended from the ceiling, her hair behaves as if under normal gravity. That gives the game away — the set is actually inverted and she is, in reality, lying on the floor. Had she truly been clinging to the ceiling, her hair would've fallen across her face.

(at around 2h 5 mins) The song Lorraine plays from a record at the end of the film is track five on side one of that album, yet the stylus shown in the shot is resting on track one.

(at about the two-hour mark) During the film's climax, as Ed clings to Janet outside her bedroom window, Lorraine hurries over and drags them back inside. "Janet" is clearly a dummy.

At the 2-hour 5-minute mark Janet tells Lorraine "You said one person could change everything but I've got two". The coloured contact lens Janet is wearing slips, partially revealing the actress's true eye colour.