Having an absolute nightmare

Hey guys, 

So I've been at this for quite a while. I currently play on a server with me and a buddy of mine. We have around 5-10 mods on there and they're pretty light on the system, however, we're looking to start getting into some serious modding on another server. As of right now the standard server has 2gb of ram allocated but I'm trying to increase it on the more heavily modded server to make sure it can keep up with the demand.

I've allocated 8GB of RAM in the user_jvm_args.txt file

# Xmx and Xms set the maximum and minimum RAM usage, respectively.
# They can take any number, followed by an M or a G.
# M means Megabyte, G means Gigabyte.
# For example, to set the maximum to 3GB: -Xmx3G
# To set the minimum to 2.5GB: -Xms2500M
-Xms2G
# A good default for a modded server is 4GB.
# Uncomment the next line to set it.
-Xmx8G

but nothing changed as i expected event though I followed someone else's guidance, so i went into my run.bat file and was presented with this.

@echo off
REM Forge requires a configured set of both JVM and program arguments.
REM Add custom JVM arguments to the user_jvm_args.txt
REM Add custom program arguments {such as nogui} to this file in the next line before the %* or
REM  pass them to this script directly
java @user_jvm_args.txt @libraries/net/minecraftforge/forge/1.20.1-47.1.46/win_args.txt %*
pause

I've tried adding a few different arguments in there but when I run the bat file and the GUI pops up it reads that there's either an error or it cant find my Jar file which is in the Version file. I then take the Jar file and move it out of it so there is a direct route to make sure there's no confusion but I still get the same error.

one example is 

Error: Unable to initialize main class net.minecraft.server.Main
Caused by: java.lang.NoClassDefFoundError: joptsimple/ValueConverter

and the argument I'm using is 

@echo off
java -Xmx8G -Xms2G -jar server-1.20.1.jar --nogui
PAUSE

I've been at this for literally months, researching, learning and just trying different things out. I'm hoping someone can either just give me an argument that will work or explain what I need to do, just anything. I'd appreciate the help.

Your fellow gamer, B.

Edited October 1, 20232 yr by BenignGamer