DaemonUmbra

So you've Set your PC to have a static IP on your LAN Set your router to send incoming traffic on port 25565 to your PC on port 25565, and Set your firewall to allow Java through.

I would assume by "open to connections" you mean you've done your port forwarding? Hamachi is a VPN client that would allow your friends to connect without port forwarding your router, although some people have issues with lag when using Hamachi.

Can I have you confirm the URL you're downloading the installer from?

Not sure what you mean by "when I get close". Are you referring to your browser stopping your download of the installer?

When you backdated Forge did you run the installer or just grab the universal?

debug.log has more information than latest.log, but I have a hunch... are you running the game fullscreen? If so try going into options.txt and setting fullscreen to false.

Then I'm not sure there's anything that can be done other than removing Optifine, sorry.

Not the shaders folder, did you install a mod called shadersmod?

How long is "indefinitely"? I assume you left it overnight to come to this conclusion? Try removing shadersmod.

I believe this is related to Mojang's change to the 1.12 asset manifest yesterday that broke lang parsing until Grum hacked a fix, try deleting .minecraft/assets/indexes/1.12.json, this will force your launcher to download a fresh one with Grum's fix. https://github.com/MinecraftForge/MinecraftForge/pull/5105#issuecomment-413663474

Please provide debug.log, it has more information in it but I can't promise anything, sadly.

The display not created one I've seen when the game was unable to go into fullscreen during load for one reason or another, in your .minecraft folder open options.txt and use Ctrl+F to find fullscreen, set it to false. I believe the Pixelmon issue was due to a change that briefly appeared in the Asset manifest earlier today, the fix is going to .minecraft/assets/indexes and deleting 1.12.json, a fixed version is live now (Thanks Grum) that should run without that issue.

Well we expect that you will allow us to help you rather than call us idiots. I'm trying to help you here and rather than helpfully answer my questions you keep shoving a single line of the crash report into my face as if it's sufficient to solve your issue. Was your Vanilla jar installed by the Forge installer or did you provide it? If you provided it what is its name?

A simple "Yes" would have sufficed. What I am trying to do here is determine the cause while you shove the symptom in my face. That library is provided by Vanilla, not by Forge, and the fact that Forge cannot find it suggests that the installation went wrong or was tampered with afterwards.

Does your Forge server jar have the vanilla server jar next to it?

What I had meant about rebooting the PC was not just to make sure the variable was set, but also to make sure Gradle restarted and got a fresh environment as well.

I'm not a Linux wizard (as evidenced above), but I'm fairly certain Linux doesn't have drive letters

I am asking about during installation, not when you are trying to run the server.

I can barely understand what you just said. So you're using the Windows variant of the installer? You got it from http://files.minecraftforge.net? When you ran it there were no windows popping up that mentioned errors or anything else about being unable to download any files? And when it was done you didn't delete anything, correct?

And the installer didn't give you any errors?

Please do not hijack threads, make your own.

Please post the appropriate log for your version as described in my signature below.

Don’t make launchers.

You have Java 9+ installed, you need to use Java 8

Can you post the server's debug.log?