When you finished Scorch you normally enter the tunnel leading to the sewers and then "use" (shift key or whatever your use key is) the lever. This triggers a delay (a few seconds) and then teleports you to the sewers (the game has to load, so even if it's looking similar after it, the character is game-technically in a new area).
Now, the mistake that some people are making (including me, but I did it with intention because I already suspected this to be the cause) is pressing the use key two times before the sewers are loaded. The game remembers this, and so, as soon as you leave fargrove you're again in the area where the lever is (yes, the entire wilderness is a single giant area) so the game thinks you pushed the lever a short time ago so you're sent to the sewers again. The problem is that while the game saves how often you pushed the lever, it does not save the opening status of the Fargrove west gate. Since you're teleported while the gate is opening, the opening sequence cannot continue and the game will forget about the gate not being raised completely while you're trying to get through the sewers again.
Hopefully this isn't known yet because if it is, this thread will be useless. feel free to test and confirm. And remember, you can always workaround the bug if you do have it - just exit to the south gate. (If the south gate wouldn't exist, there wouldn't be any way to workaround this bug, but luckily the gate exists, eh?
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