Whenever I hit the enderdragon / get him to a certain hp, my game crashes

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In case of a game crash, please also attach the crash log from [minecraft/crash-reports/crash-<DATE>-client.txt|http://hopper.minecraft.net/help/finding-minecraft-data-folder].

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its not giving any crash reports when it crashes, but i copied the game output after one of the crashes
Completely ignored arguments: [--nativeLauncherVersion, 307]
[21:59:48] [Client thread/INFO]: Setting user: ArenSpace
[21:59:50] [Client thread/INFO]: LWJGL Version: 2.9.4
[21:59:50] [Client thread/INFO]: Reloading ResourceManager: Default, faithful32pack.zip
[21:59:50] [Sound Library Loader/INFO]: Starting up SoundSystem...
[21:59:51] [Thread-5/INFO]: Initializing LWJGL OpenAL
[21:59:51] [Thread-5/INFO]: (The LWJGL binding of OpenAL. For more information, see http://www.lwjgl.org)
[21:59:51] [Thread-5/INFO]: OpenAL initialized.
[21:59:51] [Sound Library Loader/INFO]: Sound engine started
[21:59:53] [Client thread/INFO]: Created: 2048x1024 textures-atlas
[21:59:58] [Server thread/INFO]: Starting integrated minecraft server version 1.11.2
[21:59:58] [Server thread/INFO]: Generating keypair
[21:59:59] [Server thread/INFO]: Preparing start region for level 0
[22:00:00] [Server thread/INFO]: Preparing spawn area: 11%
[22:00:00] [Server thread/INFO]: Changing view distance to 9, from 10
[22:00:04] [Server thread/INFO]: ArenSpace[local:E:d8c3dad4] logged in with entity id 195 at (20.73112005774471, 61.0, -1.0232663040423804)
[22:00:04] [Server thread/INFO]: ArenSpace joined the game
[22:00:04] [Server thread/WARN]: Keeping entity minecraft:enderman that already exists with UUID 0b82147c-3640-4637-b342-5f9419767be7
[22:00:04] [Server thread/INFO]: Saving and pausing game...
[22:00:04] [Server thread/INFO]: Saving chunks for level 'Somtehn'/Overworld
[22:00:05] [Server thread/INFO]: Saving chunks for level 'Somtehn'/Nether
[22:00:05] [Server thread/INFO]: Saving chunks for level 'Somtehn'/The End
[22:00:06] [Server thread/INFO]: Scanning for legacy world dragon fight...
[22:00:06] [Server thread/INFO]: Found that the dragon has not yet been killed in this world.
[22:00:06] [Server thread/INFO]: Found that there's a dragon still alive (yb['Ender Dragon'/253, l='Somtehn', x=35.24, y=94.05, z=-34.92])
[22:00:06] [Server thread/INFO]: But we didn't have a portal, let's remove it.
[22:00:13] [Thread-5/ERROR]: Error in class 'CodecJOrbis'
[22:00:13] [Thread-5/ERROR]: Ogg header not recognized in method 'readHeader'.
[22:00:13] [Thread-5/ERROR]: Error in class 'CodecJOrbis'
[22:00:13] [Thread-5/ERROR]: Error reading the header

Please attach the crash report, not the log.

Looks like MC-2249, possibly caused by corrupted sound file, please try the steps provided there

sorry FVbico, it doesnt give me a crash report, the minecraft window stops responding and then it closes

my game crashes

and then it closes

This both indicates that a crash report is shown in the launcher.