the moment a world loads it crashes
[11:42:33 INFO]: Minecraft Launcher 1.6.61 (through bootstrap 100) started on windows...
[11:42:33 INFO]: Current time is Apr 8, 2017 11:42:33 AM
[11:42:33 INFO]: System.getProperty('os.name') == 'Windows 8.1'
[11:42:33 INFO]: System.getProperty('os.version') == '6.3'
[11:42:33 INFO]: System.getProperty('os.arch') == 'x86'
[11:42:33 INFO]: System.getProperty('java.version') == '1.8.0_101'
[11:42:33 INFO]: System.getProperty('java.vendor') == 'Oracle Corporation'
[11:42:33 INFO]: System.getProperty('sun.arch.data.model') == '32'
[11:42:33 INFO]: proxy == DIRECT
[11:42:33 INFO]: JFX is already initialized
[11:42:34 INFO]: Refreshing local version list...
[11:42:34 INFO]: Refreshing remote version list...
[11:42:35 INFO]: Refresh complete.
[11:42:36 INFO]: Loaded 1 profile(s); selected 'DAsher_2003__'
[11:42:36 INFO]: Refreshing auth...
[11:42:36 INFO]: Logging in with access token
[11:42:36 ERROR]: Exception whilst logging into profile
com.mojang.authlib.exceptions.InvalidCredentialsException: Invalid token.
at com.mojang.authlib.yggdrasil.YggdrasilAuthenticationService.makeRequest(YggdrasilAuthenticationService.java:63) ~[launcher.jar:1.6.61]
at com.mojang.authlib.yggdrasil.YggdrasilUserAuthentication.logInWithToken(YggdrasilUserAuthentication.java:132) ~[launcher.jar:1.6.61]
at com.mojang.authlib.yggdrasil.YggdrasilUserAuthentication.logIn(YggdrasilUserAuthentication.java:55) ~[launcher.jar:1.6.61]
at net.minecraft.launcher.Launcher.ensureLoggedIn(Launcher.java:215) [launcher.jar:1.6.61]
at net.minecraft.launcher.Launcher$2.run(Launcher.java:169) [launcher.jar:1.6.61]
at java.util.concurrent.Executors$RunnableAdapter.call(Unknown Source) [?:1.8.0_101]
at java.util.concurrent.FutureTask.run(Unknown Source) [?:1.8.0_101]
at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source) [?:1.8.0_101]
at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source) [?:1.8.0_101]
at java.lang.Thread.run(Unknown Source) [?:1.8.0_101]