Minecraft Forums

I started having problems when i updated to 15w50. for some reason I'm not getting any sound. I tried reinstalling Minecraft and that didn't do anything. It's not the in game sliders or the volume mixer ones either. I even changed back to 1.8.8 for a server and still no sound. also recently I tried to go to some earlier versions but downloading them doesn't even work. It stops when it gets to the sound files and gives this error: "[20:11:20 ERROR]: Couldn't unpack natives!
java.io.FileNotFoundException: Source 'C:\Users\David\AppData\Roaming\.minecraft\assets\objects\0d\0d000710b71ca9aafabd8f587768431d0b560b32' does not exist
at org.apache.commons.io.FileUtils.copyFile(FileUtils.java:1074) ~[launcher.jar:1.6.48]
at net.minecraft.launcher.game.MinecraftGameRunner.reconstructAssets(MinecraftGameRunner.java:272) ~[launcher.jar:1.6.48]
at net.minecraft.launcher.game.MinecraftGameRunner.launchGame(MinecraftGameRunner.java:119) [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]"

Any suggestions on what I should do to fix this problem?