Iv'e been having the same problem so I added that to my JVM arguments in the launcher, but there is an error and it won't launch minecraft.
Here is the part of the log with the error:
[13:14:41] [main/DEBUG] [FML/]: Validating minecraft
[13:14:42] [main/DEBUG] [FML/]: Minecraft validated, launching...
[13:14:42] [main/INFO] [LaunchWrapper/]: Launching wrapped minecraft {net.minecraft.client.main.Main}
[13:14:42] [main/DEBUG] [FML/]: Runtime patching class net/minecraft/world/IBlockAccess (input size 250), found 1 patch
[13:14:42] [main/DEBUG] [FML/]: Successfully applied runtime patches for net/minecraft/world/IBlockAccess (new size 540)
[13:14:42] [main/DEBUG] [FML/]: Runtime patching class net/minecraft/block/BlockBush (input size 1432), found 1 patch
[13:14:42] [main/DEBUG] [FML/]: Successfully applied runtime patches for net/minecraft/block/BlockBush (new size 3942)
[13:14:42] [main/ERROR] [LaunchWrapper/]: Unable to launch
java.lang.reflect.InvocationTargetException
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[?:1.8.0_11]
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source) ~[?:1.8.0_11]
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source) ~[?:1.8.0_11]
at java.lang.reflect.Method.invoke(Unknown Source) ~[?:1.8.0_11]
at net.minecraft.launchwrapper.Launch.launch(Launch.java:134) [launchwrapper-1.9.jar:?]
at net.minecraft.launchwrapper.Launch.main(Launch.java:28) [launchwrapper-1.9.jar:?]
Caused by: java.lang.VerifyError: Bad type on operand stack
Exception Details:
Location:
net/minecraft/client/Minecraft.func_71411_J()V @201: invokevirtual
Reason:
Type 'net/minecraft/client/entity/EntityClientPlayerMP' (current frame, stack[1]) is not assignable to 'net/minecraft/entity/player/EntityPlayer'
Current Frame:
bci: @201
flags: { }
locals: { 'net/minecraft/client/Minecraft', top, long, long_2nd, top, long, long_2nd }
stack: { 'net/minecraft/client/audio/SoundHandler', 'net/minecraft/client/entity/EntityClientPlayerMP', float }
Bytecode:
0000000: 2ab4 010e 1301 3bb6 05e8 b805 eb99 000d
0000010: b805 ee99 0007 2ab6 05f1 2ab4 05f3 9900
0000020: 242a b403 e8c6 001d 2ab4 00f7 b405 f644
0000030: 2ab4 00f7 b605 f92a b400 f723 b505 f6a7
0000040: 000a 2ab4 00f7 b605 f92a b403 e8c6 000a
0000050: 2ab4 053e c700 132a b405 fb99 000c 2a03
0000060: b505 fb2a b605 fdb8 0600 412a b401 0e13
0000070: 0602 b605 e803 3604 1504 2ab4 00f7 b406
0000080: 05a2 000d 2ab6 0608 8404 01a7 ffed 2ab4
0000090: 010e 1306 0ab6 060d b806 0020 6537 052a
00000a0: 1306 0fb7 039b 2ab4 0254 b406 12b3 0617
00000b0: 2ab4 010e 1306 19b6 060d 2ab4 034e 2ab4
00000c0: 0533 2ab4 00f7 b405 f6b6 061d 2ab4 010e
00000d0: b606 202a b401 0e13 0622 b605 e8b8 0625
00000e0: 1141 00b8 0628 2ab4 01e2 04b6 04d2 2ab4
00000f0: 010e 1306 2ab6 05e8 110d e1b8 03a0 2ab4
0000100: 0533 c600 152a b405 33b6 062d 9900 0b2a
0000110: b402 5403 b506 302a b401 0eb6 0620 2ab4
0000120: 056c 9a00 3cb8 0234 2ab4 00f7 b405 f6b6
0000130: 0633 2ab4 010e 1306 35b6 060d 2ab4 0384
0000140: 2ab4 00f7 b405 f6b6 0638 2ab4 010e b606
0000150: 20b8 0234 2ab4 00f7 b405 f6b6 063b b805
0000160: 1b2a b401 0eb6 0620 b806 3e9a 000e 2ab4
0000170: 01a6 9900 072a b604 122a b402 54b4 0559
0000180: 9900 2f2a b402 54b4 0641 9900 252a b401
0000190: 0eb4 0644 9a00 0a2a b401 0eb6 0647 2ab4
00001a0: 010e 04b5 0644 2a16 05b7 064a a700 122a
00001b0: b401 0e03 b506 442a b806 00b5 0139 2ab4
00001c0: 02e7 b606 4d2a b401 e2b6 0515 b806 50b8
00001d0: 0625 2ab4 01e2 2ab4 019e 2ab4 01a0 b605
00001e0: 18b8 0650 b806 252a b403 842a b400 f7b4
00001f0: 05f6 b606 53b8 0650 2ab4 010e 1301 3bb6
0000200: 05e8 2ab6 051e b806 562a b401 0e13 0658
0000210: b605 e82a b401 0e13 065a b605 e82a b402
0000220: ceb9 065d 0100 2ab4 010e 1306 5fb6 060d
0000230: 2ab4 02ce b906 6201 002a b401 0eb6 0620
0000240: 2ab4 010e b606 202a 1306 64b7 039b 2a59
0000250: b406 6604 60b5 0666 2a2a b606 6999 0022
0000260: 2ab4 053e c600 1b2a b405 3eb6 066c 9900
0000270: 112a b406 6eb6 0673 9a00 0704 a700 0403
0000280: b505 f3b8 0109 2ab4 0137 1402 ad61 949b
0000290: 0060 2ab4 0666 b306 752a bb01 8959 b701
00002a0: 8ab2 0675 b605 8613 0677 b601 90b2 067c
00002b0: b605 8613 067e b601 90b6 0194 b501 3503
00002c0: b306 7c2a 59b4 0137 1402 ad61 b501 372a
00002d0: 03b5 0666 2ab4 0106 b606 812a b401 06b6
00002e0: 0684 9aff a12a b401 06b6 0687 a7ff 972a
00002f0: b401 0eb6 0620 2ab6 068a 9900 0a2a b606
0000300: 8db8 0690 b1
Stackmap Table:
same_frame(@26)
same_frame(@66)
same_frame(@73)
same_frame(@87)
same_frame(@103)
append_frame(@120,Top,Long,Integer)
chop_frame(@142,1)
append_frame(@279,Top,Long)
same_frame_extended(@350)
same_frame(@377)
same_frame(@414)
same_frame(@431)
same_frame(@446)
same_locals_1_stack_item_extended(@639,Object[#2])
full_frame(@640,{Object[#2],Top,Long,Top,Long},{Object[#2],Integer})
same_frame(@643)
same_frame_extended(@751)
same_frame(@772)
at net.minecraft.client.main.Main.main(SourceFile:72) ~[Main.class:?]
... 6 more
