I forgot to "activate" a portal leading to the next part of the forest (after the museum quest).
I tried to update the build on Steam, but I wasn't receiving the confirmation code via SMS. I updated my Steam security settings to see if that would fix the issue, and now it says I have to wait 72 hours before updating a build (??!!?) it's driving me absolutely crazy -_____-
If you really want to continue playing, I can give you a hint :
You can open the console by pressing Left Alt + é, then type "SampleScene" (careful to the space at the beginning). You'll spawn in an area with lots of doors at your right; take the one labeled "Forest Trench."
Sorry for the inconvenience. The game will be updated in three days, then normally.