Fixed an issue with directional gated tracks, which, like the last fix, are a new Railcraft feature. I really need to start reading those changelogs, huh. Anyways, here's the updated file:
Railcraft-3D-mc-1.12.2.zip
There are a few more minor issues on my radar that will require much more work to fix (re-doing entire models in some cases) and I simply haven't had time to do it. They will only bother you if I tell you where to look for them, so best to keep it under wraps for now.