FMLTweaker Error

[Nintenso Phyrx]

[21:21:13] [main/INFO]: Loading tweak class name net.minecraftforge.fml.common.launcher.FMLTweaker
[21:21:14] [main/ERROR]: Unable to launch
java.lang.ClassNotFoundException: net.minecraftforge.fml.common.launcher.FMLTweaker
    at java.net.URLClassLoader.findClass(Unknown Source) ~[?:1.8.0_221]
    at java.lang.ClassLoader.loadClass(Unknown Source) ~[?:1.8.0_221]
    at sun.misc.Launcher$AppClassLoader.loadClass(Unknown Source) ~[?:1.8.0_221]
    at java.lang.ClassLoader.loadClass(Unknown Source) ~[?:1.8.0_221]
    at net.minecraft.launchwrapper.LaunchClassLoader.findClass(LaunchClassLoader.java:106) ~[launchwrapper-1.12.jar:?]
    at java.lang.ClassLoader.loadClass(Unknown Source) ~[?:1.8.0_221]
    at java.lang.ClassLoader.loadClass(Unknown Source) ~[?:1.8.0_221]
    at java.lang.Class.forName0(Native Method) ~[?:1.8.0_221]
    at java.lang.Class.forName(Unknown Source) ~[?:1.8.0_221]
    at net.minecraft.launchwrapper.Launch.launch(Launch.java:98) [launchwrapper-1.12.jar:?]
    at net.minecraft.launchwrapper.Launch.main(Launch.java:28) [launchwrapper-1.12.jar:?]
Java HotSpot(TM) 64-Bit Server VM warning: Using incremental CMS is deprecated and will likely be removed in a future release

 

I'm directly going into the topic

Recently I downloaded a mod named ModBlocker for a Pixelmon server

Besides that I have OptiFine E_3 and Pixelmon 7.0.8

When I don't use ModBlocker, game starts but the server will not let me enter

When I do, it doesn't

What should I do?

[Edit: I also searched for a solution for this. It's been like 8+ hours but i can't find anything]

Edited October 13, 2019 by Nintenso Phyrx

[DaemonUmbra]

How did you install Forge?

[Nintenso Phyrx]

  On 10/14/2019 at 3:35 AM, DaemonUmbra said:

How did you install Forge?

Expand  

I installed it right from its original website i remember

[DaemonUmbra]

You downloaded which file from what URL?