forge 1.12.2 failing at akka-actor_2.11-2.3.3.jar.pack.xz library install

trying to install forge 1.12.2, Minecraft version 1.15.2, and stopping while trying to unpack akka-actor_2.11-2.3.3.jar.pack.xz file. getting this from the log:

S

etting up logger: /Users/emmacairns/Downloads/forge-1.12.2-14.23.5.2838-installer.jar.log

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

Checking "/Users/emmacairns/Library/Application Support/minecraft/libraries/com/typesafe/akka/akka-actor_2.11/2.3.3/akka-actor_2.11-2.3.3.jar" internal checksums

    checksums.sha1 was not found, validation failed

Downloading library com.typesafe.akka:akka-actor_2.11:2.3.3

Unpacking packed file akka-actor_2.11-2.3.3.jar.pack.xz

  Signed

  Checksum Length: 140942

  Total Length:    2606968

  Temp File:       /var/folders/92/bxjr4frj05vghpyj2ncmhphc0000gn/T/art4843519418397437990.pack

Exception in thread "main" java.lang.reflect.InvocationTargetException

at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)

at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)

at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)

at java.base/java.lang.reflect.Method.invoke(Method.java:564)

at net.minecraftforge.installer.Java6Gate.main(Java6Gate.java:48)

Caused by: java.lang.NoClassDefFoundError: java/util/jar/Pack200

at net.minecraftforge.installer.DownloadUtils.unpackLibrary(DownloadUtils.java:253)

at net.minecraftforge.installer.DownloadUtils.downloadInstalledLibraries(DownloadUtils.java:89)

at net.minecraftforge.installer.ClientInstall.run(ClientInstall.java:131)

at net.minecraftforge.installer.InstallerAction.run(InstallerAction.java:43)

at net.minecraftforge.installer.InstallerPanel.run(InstallerPanel.java:406)

at net.minecraftforge.installer.SimpleInstaller.launchGui(SimpleInstaller.java:168)

at net.minecraftforge.installer.SimpleInstaller.main(SimpleInstaller.java:54)

... 5 more

Caused by: java.lang.ClassNotFoundException: java.util.jar.Pack200

at java.base/jdk.internal.loader.BuiltinClassLoader.loadClass(BuiltinClassLoader.java:602)

at java.base/jdk.internal.loader.ClassLoaders$AppClassLoader.loadClass(ClassLoaders.java:178)

at java.base/java.lang.ClassLoader.loadClass(ClassLoader.java:522)

... 12 more

no idea what I'm doing wrong, been trying to work it out for a few hours. if anyone knows anything, would really appreciate it!