[2019] Ahead of the Patch Notes, here's how to add 3.9's passive tree to Path of Building as soon as possible

The passive tree in PoB is usually updated within a few hours of the patch notes dropping, but it's pretty simple to just add it to PoB yourself ahead of time. Until it's actually updated, PoB probably won't support any new modifiers like the new Phys Damage Reduction stuff on enemies, but you can at least start planning your trees a little faster.

1. Click this link to download a .zip file containing the new passive tree graphics and skill tree: https://web.poecdn.com/public/news/2019-12-11/390_V2PassiveSkillTree.zip
2. Navigate to (by default) C:\ProgramData\Path of Building\TreeData. Create a folder called "3_9", similar to the other folders that are there.
3. From the .zip you downloaded, extract data.txt into the folder you made, then open the assets folder and also extract the images groups-3, skills-3, and skills-disabled-3
4. Move up a couple of folders, to C:\ProgramData\Path of Building. Open GameVersions.lua in a text editor(if you've never done that before, right click -> open with -> Notepad). Replace the contents of the file with the contents of this pastebin: https://pastebin.com/1P6LpJQn (scroll to the bottom and copy the raw paste data, then paste that into the lua file and save it)
5. Restart PoB and your default tree should now be the 3.9 tree! Your builds from 3.8 will need to be updated if it all worked correctly.
6. PoB will now always show that there's an update ready, but do NOT update or the changes you made will be reverted and you'll have to do them again! If you click "Update Ready" and there's no changelog in the popup, the update isn't real. When a changelog shows up, you should be able to update safely.

Also, while I have all the PoB users here, you should use LocalIdentity1's fork of PoB instead of the regular one! It has a ton more features than the regular build of PoB, including things like Pantheon configuration and Impale damage calculations. It's got a lot of contributions from people in the whole community. I've personally contributed a few things like better Shock configuration(enter an exact Shock value!), support for Elusive and modifiers to it, and support for Elementalist's Golem nodes. If you've ever been upset that something didn't work on the regular PoB build, try the fork, because the fork probably supports it. And it will, of course, update alongside any features that Openarl adds to regular PoB. Read more information here: https://www.reddit.com/r/pathofexile/comments/deon82/localidentitys_path_of_building_v141514_fork/

EDIT: Seems like the json data that GGG gave us is actually broken somehow, because it's causing an error in PoB if you try to do what I've described. I've used this method for several leagues now, and even tested it with the 3.8 data before I made the post to make sure I knew how to do it, and it's worked properly every other time. Check back in a bit to see if they update the data.

EDIT2: /u/TrashCaster found a fix for the JSON data down below, I've changed the link to be his upload of the fixed file. I downloaded it and tested it and it works perfectly!

EDIT3: GGG has updated the tree data. The Ascendancy classes were in the data twice, which was causing errors because programs were expecting a certain number of Ascendancies. All good now!