java.net.preferIPv4Stack=true
Considering library net.minecraftforge:forge:1.12.2-14.23.5.2838: Not Downloading {Wrong Side}
Considering library net.minecraft:launchwrapper:1.12: Not Downloading {Wrong Side}
Considering library org.ow2.asm:asm-all:5.2
Considering library org.jline:jline:3.5.1: Not Downloading {Wrong Side}
Considering library net.java.dev.jna:jna:4.4.0: Not Downloading {Wrong Side}
Considering library com.typesafe.akka:akka-actor_2.11:2.3.3
Considering library com.typesafe:config:1.2.1
Considering library org.scala-lang:scala-actors-migration_2.11:1.1.0
Considering library org.scala-lang:scala-compiler:2.11.1
Considering library org.scala-lang.plugins:scala-continuations-library_2.11:1.0.2
Checking "C:\Users\<username>\AppData\Roaming\.minecraft\libraries\org\scala-lang\plugins\scala-continuations-library_2.11\1.0.2\scala-continuations-library_2.11-1.0.2.jar" internal checksums
    checksums.sha1 was not found, validation failed
Downloading library org.scala-lang.plugins:scala-continuations-library_2.11:1.0.2
Trying unpacked library org.scala-lang.plugins:scala-continuations-library_2.11:1.0.2
Checking "C:\Users\<username>\AppData\Roaming\.minecraft\libraries\org\scala-lang\plugins\scala-continuations-library_2.11\1.0.2\scala-continuations-library_2.11-1.0.2.jar" internal checksums
    checksums.sha1 was not found, validation failed
File not found in installer archive: /maven/org/scala-lang/plugins/scala-continuations-library_2.11/1.0.2/scala-continuations-library_2.11-1.0.2.jar
Considering library org.scala-lang.plugins:scala-continuations-plugin_2.11.1:1.0.2
Checking "C:\Users\<username>\AppData\Roaming\.minecraft\libraries\org\scala-lang\plugins\scala-continuations-plugin_2.11.1\1.0.2\scala-continuations-plugin_2.11.1-1.0.2.jar" internal checksums
    checksums.sha1 was not found, validation failed
Downloading library org.scala-lang.plugins:scala-continuations-plugin_2.11.1:1.0.2
Trying unpacked library org.scala-lang.plugins:scala-continuations-plugin_2.11.1:1.0.2
Checking "C:\Users\<username>\AppData\Roaming\.minecraft\libraries\org\scala-lang\plugins\scala-continuations-plugin_2.11.1\1.0.2\scala-continuations-plugin_2.11.1-1.0.2.jar" internal checksums
    checksums.sha1 was not found, validation failed
File not found in installer archive: /maven/org/scala-lang/plugins/scala-continuations-plugin_2.11.1/1.0.2/scala-continuations-plugin_2.11.1-1.0.2.jar
Considering library org.scala-lang:scala-library:2.11.1
Considering library org.scala-lang:scala-parser-combinators_2.11:1.0.1
Considering library org.scala-lang:scala-reflect:2.11.1
Considering library org.scala-lang:scala-swing_2.11:1.0.1
Considering library org.scala-lang:scala-xml_2.11:1.0.2
Considering library lzma:lzma:0.0.1: Not Downloading {Wrong Side}
Considering library net.sf.jopt-simple:jopt-simple:5.0.3: Not Downloading {Wrong Side}
Considering library java3d:vecmath:1.5.2
Considering library net.sf.trove4j:trove4j:3.0.3
Considering library org.apache.maven:maven-artifact:3.5.3

Here is the entire log. I'm trying to get RLCraft to work. 

• Java is updated.
• I used the jar version of the download.

1.12 is no longer supported on this forum.
Please update to a modern version of Minecraft to receive support.

7 minutes ago, Luis_ST said:

1.12 is no longer supported on this forum.
Please update to a modern version of Minecraft to receive support.

RLCraft doesn't support above 1.12 does it?