Lazy and Stupid
For those who don't know, the "family went missing and everyone denies their existence" is an old urban legend. I first heard of it when I was a little kid and read Scary Stories To Tell in the Dark 3
So there is nothing original in the premise. That is fine, with old urban legends it is ok to re-use the basic premise as long as you spin it into something unique and add some elements of originality
But this just lazily follows old, over-done movie tropes. This was directed by the same guy who directed The Machinist, and it's kind of sad to see that he was comfortable basically treading the exact same ground again (this time much less effectively, though)
As for Sam Worthington...bless his soul. You can tell he is really trying. And in some scenes he can be sort of effective. But for the most part he resorts to hammy over-acting when the tensions ratchets up. He is a daytime TV caliber actor that somehow lucked into a movie career
The whole thing was like a very bad Twilight Zone episode. I predicted all of the story beats as soon as the main character woke up from his nap. I only kept watching because I felt that there was NO WAY a movie in 2019 could be THAT predictable and lazy. I was WRONG