BaTaTa_Adb

Could you show your output on "java -version" and "echo %JAVA_HOME%" ?

@echo off "C:\Program Files\Java\jre1.8.0_331\bin\java.exe" -Xms4G -Xmx8G -XX:+UseG1GC -XX:+ParallelRefProcEnabled -XX:MaxGCPauseMillis=200 -XX:+UnlockExperimentalVMOptions -XX:+DisableExplicitGC -XX:+AlwaysPreTouch -XX:G1NewSizePercent=30 -XX:G1MaxNewSizePercent=40 -XX:G1HeapRegionSize=8M -XX:G1ReservePercent=20 -XX:G1HeapWastePercent=5 -XX:G1MixedGCCountTarget=4 -XX:InitiatingHeapOccupancyPercent=15 -XX:G1MixedGCLiveThresholdPercent=90 -XX:G1RSetUpdatingPauseTimePercent=5 -XX:SurvivorRatio=32 -XX:+PerfDisableSharedMem -XX:MaxTenuringThreshold=1 -Dusing.aikars.flags=https://mcflags.emc.gs -Daikars.new.flags=true -jar forge-1.12.2-14.23.5.2860.jar nogui Here's my start.bat if you want to take a look. I grab the java from "C:\Program Files\Java\jre1.8.0_331\bin\" -> which is my JAVA_HOME environmental variable. Then I run the jar file "forge-1.12.2-14.23.5.2860.jar"

I'm quite certain that you are using a more recent version of java that is not supported by older forge. For 1.12.2 forge, I use oracle's java version "1.8.0_333" (java 8). https://www.oracle.com/java/technologies/downloads/#java8-windows The installation process is not very easy, so I would recommend following a tutorial (for example). Best of luck.