Im trying to install forge 1.7.10 on a mac and it gets stuck at downloading libraries, unpacking packed file akka-actor_2.11-2.3.3.jar.pack.xz
this is the installer log
Considering library net.minecraftforge:forge:1.7.10-10.13.4.1558-1.7.10: Not Downloading
Considering library net.minecraft:launchwrapper:1.12: Not Downloading
Considering library org.ow2.asm:asm-all:5.0.3: Not Downloading
Considering library com.typesafe.akka:akka-actor_2.11:2.3.3
Checking "/Users/23stone/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/1l/lnjlgyzn5nbbtf5pt8ptx61c0000gq/T/art2414281012652444883.pack
Exception in thread "main" java.lang.NoClassDefFoundError: java/util/jar/Pack200
at net.minecraftforge.installer.DownloadUtils.unpackLibrary(DownloadUtils.java:264)
at net.minecraftforge.installer.DownloadUtils.downloadInstalledLibraries(DownloadUtils.java:111)
at net.minecraftforge.installer.ClientInstall.run(ClientInstall.java:135)
at net.minecraftforge.installer.InstallerAction.run(InstallerAction.java:42)
at net.minecraftforge.installer.InstallerPanel.run(InstallerPanel.java:290)
at net.minecraftforge.installer.SimpleInstaller.launchGui(SimpleInstaller.java:154)
at net.minecraftforge.installer.SimpleInstaller.main(SimpleInstaller.java:40)
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)
... 7 more