Here is the error file:

Considering library net.minecraftforge:forge:1.11.2-13.20.0.2228: Not Downloading {Wrong Side}
Considering library net.minecraft:launchwrapper:1.12: Not Downloading {Wrong Side}
Considering library org.ow2.asm:asm-all:5.0.3: Not Downloading {Wrong Side}
Considering library jline:jline:2.13: 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\User\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 validated successfully
    Jar contents validated successfully
Considering library org.scala-lang.plugins:scala-continuations-plugin_2.11.1:1.0.2
Checking "C:\Users\User\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 validated successfully
    Jar contents validated successfully
Considering library org.scala-lang:scala-library:2.11.1
Checking "C:\Users\User\AppData\Roaming\.minecraft\libraries\org\scala-lang\scala-library\2.11.1\scala-library-2.11.1.jar" internal checksums
Exception in thread "main" java.lang.IllegalArgumentException: MALFORMED
    at java.util.zip.ZipCoder.toString(Unknown Source)
    at java.util.zip.ZipCoder.toStringUTF8(Unknown Source)
    at java.util.zip.ZipInputStream.readLOC(Unknown Source)
    at java.util.zip.ZipInputStream.getNextEntry(Unknown Source)
    at java.util.jar.JarInputStream.getNextEntry(Unknown Source)
    at java.util.jar.JarInputStream.getNextJarEntry(Unknown Source)
    at net.minecraftforge.installer.DownloadUtils.validateJar(DownloadUtils.java:287)
    at net.minecraftforge.installer.DownloadUtils.checksumValid(DownloadUtils.java:137)
    at net.minecraftforge.installer.DownloadUtils.downloadInstalledLibraries(DownloadUtils.java:53)
    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:165)
    at net.minecraftforge.installer.SimpleInstaller.main(SimpleInstaller.java:51)

Can anyone tell me what's the problem???
 

15 hours ago, diesieben07 said:

Delete  C:\Users\User\AppData\Roaming\.minecraft\libraries\org\scala-lang\scala-library\2.11.1\scala-library-2.11.1.jar and try again.

I have this problem as well, and i've tried this multiple times and it still gives me the same "Unable to save download. lzma-0.0.1.jar" error message when i hit "play"

Actually i fixed it, i went into "launch options" within the minecraft launcher, picked the forge profile, and set the version to 1.11.2. Wish I woulda tried that sooner...

That doesnt fix it, that just stops loading Forge.

And don't hijack other's threads.

Ah, i see, well i guess back at square one then. Would you rather me make another thread for the same issue?