crash in multiplayer

when i get on to multiplayer everything looks fine but when i get to spawn it quits the game and says ([18:12:17] [Client thread/INFO]: Setting user: starblackfire
[18:12:17] [Client thread/INFO]: (Session ID is token:0a70c2c5bda7452ab772047cd1c35735:4efc3bf260ce486cb31c777163aeca3e)
[18:12:19] [Client thread/INFO]: LWJGL Version: 2.9.4
[18:12:19] [Client thread/INFO]: Reloading ResourceManager: Default
[18:12:20] [Sound Library Loader/INFO]: Starting up SoundSystem...
[18:12:20] [Thread-6/INFO]: Initializing LWJGL OpenAL
[18:12:20] [Thread-6/INFO]: (The LWJGL binding of OpenAL. For more information, see http://www.lwjgl.org)
[18:12:20] [Thread-6/INFO]: OpenAL initialized.
[18:12:20] [Sound Library Loader/INFO]: Sound engine started
[18:12:21] [Twitch authenticator/ERROR]: Given twitch access token is invalid
[18:12:22] [Client thread/INFO]: Created: 512x512 textures-atlas
[18:12:36] [Client thread/INFO]: Connecting to us.mineplex.com., 25565
[18:12:39] [Client thread/INFO]: [CHAT]
[18:12:39] [Client thread/INFO]: [CHAT] 14 mashellita oh!
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1. A fatal error has been detected by the Java Runtime Environment:
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2. EXCEPTION_ACCESS_VIOLATION (0xc0000005) at pc=0x000000001b85c933, pid=4644, tid=12932
   #

3. JRE version: Java(TM) SE Runtime Environment (8.0_25-b18) (build 1.8.0_25-b18)

4. Java VM: Java HotSpot(TM) 64-Bit Server VM (25.25-b02 mixed mode windows-amd64 compressed oops)

5. Problematic frame:

6. C [ig7icd64.dll+0x6c933]
   #

7. Failed to write core dump. Minidumps are not enabled by default on client versions of Windows
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8. An error report file with more information is saved as:

9. C:\Program Files (x86)\Minecraft\hs_err_pid4644.log
   #

10. If you would like to submit a bug report, please visit:

11. http://bugreport.sun.com/bugreport/crash.jsp

12. The crash happened outside the Java Virtual Machine in native code.

13. See problematic frame for where to report the bug.
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    AL lib: (EE) alc_cleanup: 1 device not closed
    Java HotSpot(TM) 64-Bit Server VM warning: Using incremental CMS is deprecated and will likely be removed in a future release
    ) i dont no wat it means and i need it to be fixed and i need you to help me