Says this:

arch='null'}}], natives={WINDOWS=natives-windows-${arch}}, extract=com.mojang.launcher.versions.ExtractRules@1b655}], mainClass='net.minecraft.client.main.Main', jar='null', minimumLauncherVersion=14}
[08:53:21 ERROR]: Couldn't unpack natives!
java.util.zip.ZipException: zip file is empty
at java.util.zip.ZipFile.open(Native Method) ~[?:1.8.0_25]
at java.util.zip.ZipFile.<init>(ZipFile.java:220) ~[?:1.8.0_25]
at java.util.zip.ZipFile.<init>(ZipFile.java:150) ~[?:1.8.0_25]
at java.util.zip.ZipFile.<init>(ZipFile.java:164) ~[?:1.8.0_25]
at net.minecraft.launcher.game.MinecraftGameRunner.unpackNatives(MinecraftGameRunner.java:376) ~[launcher.jar:1.6.48]
at net.minecraft.launcher.game.MinecraftGameRunner.launchGame(MinecraftGameRunner.java:111) [launcher.jar:1.6.48]
at com.mojang.launcher.game.runner.AbstractGameRunner.onDownloadJobFinished(AbstractGameRunner.java:186) [launcher.jar:1.6.48]
at com.mojang.launcher.updater.download.DownloadJob.popAndDownload(DownloadJob.java:122) [launcher.jar:1.6.48]
at com.mojang.launcher.updater.download.DownloadJob.access$000(DownloadJob.java:12) [launcher.jar:1.6.48]
at com.mojang.launcher.updater.download.DownloadJob$1.run(DownloadJob.java:86) [launcher.jar:1.6.48]
at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511) [?:1.8.0_25]
at java.util.concurrent.FutureTask.run(FutureTask.java:266) [?:1.8.0_25]
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142) [?:1.8.0_25]
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617) [?:1.8.0_25]
at java.lang.Thread.run(Thread.java:745) [?:1.8.0_25]