DaemonUmbra

Please read the Logs section of my signature below and provide the appropriate log in the appropriate manner.

I would also suggest updating to a modern version.

1.8.9 is no longer supported on this forum due to its age. Please update to a modern version of Minecraft to receive support.

Remove Damage Indicators

Please read the Logs section of my signature below and provide the appropriate log in the appropriate manner.

What version are you playing?

Shaders are entirely the realm of Optifine

Congrats, you downloaded a program that asks you to install crap on your computer then downloads the wrong Forge installer. Only get Forge from https://files.minecraftforge.net/. I would also recommend running a virus scan on your computer.

This is not new and there's nothing we can do about it

That's an old version, try a new one. Beyond that try running it from terminal and tell us what it says

I'm assuming the installer is in your downloads folder? So far you have attempted this command in your user folder and in a .minecraft/forge folder

Launcher Installations

Windows is hiding the file extension from you while the command you need to run requires it

Please read the Logs section of my signature below and provide the appropriate log in the appropriate manner.

Try deleting fml.toml from your config folder

Remove or Update Optifine

1.8.9 is no longer supported on this forum due to its age. Please update to a modern version of Minecraft to receive support.

1.8.9 is no longer supported on this forum due to its age. Please update to a modern version of Minecraft to receive support.

So intellij detects it as a gradle project just fine?

By "A LOT" you don't mean every tick, do you?

Can you provide your code in a GitHub repo?

Looks like you have a json error

So you're in a Forge workspace editing vanilla directly?

This isn't a Forge crash, but it looks like you managed to make a json invalid

I'm asking because I don't see that stacktrace go through a method called "teleport" and I don't see obvious non-vanilla packages in it either.