I get this error when I load up a world:

 

com.mojang.authlib.exceptions.AuthenticationException: The client has sent too many requests within a certain amount of time
at com.mojang.authlib.yggdrasil.YggdrasilAuthenticationService.makeRequest(YggdrasilAuthenticationService.java:65) ~[YggdrasilAuthenticationService.class:?]
at com.mojang.authlib.yggdrasil.YggdrasilMinecraftSessionService.fillGameProfile(YggdrasilMinecraftSessionService.java:158) [YggdrasilMinecraftSessionService.class:?]
at com.mojang.authlib.yggdrasil.YggdrasilMinecraftSessionService$1.load(YggdrasilMinecraftSessionService.java:53) [YggdrasilMinecraftSessionService$1.class:?]
at com.mojang.authlib.yggdrasil.YggdrasilMinecraftSessionService$1.load(YggdrasilMinecraftSessionService.java:50) [YggdrasilMinecraftSessionService$1.class:?]
at com.google.common.cache.LocalCache$LoadingValueReference.loadFuture(LocalCache.java:3524) [guava-17.0.jar:?]
at com.google.common.cache.LocalCache$Segment.loadSync(LocalCache.java:2317) [guava-17.0.jar:?]
at com.google.common.cache.LocalCache$Segment.lockedGetOrLoad(LocalCache.java:2280) [guava-17.0.jar:?]
at com.google.common.cache.LocalCache$Segment.get(LocalCache.java:2195) [guava-17.0.jar:?]
at com.google.common.cache.LocalCache.get(LocalCache.java:3934) [guava-17.0.jar:?]
at com.google.common.cache.LocalCache.getOrLoad(LocalCache.java:3938) [guava-17.0.jar:?]
at com.google.common.cache.LocalCache$LocalLoadingCache.get(LocalCache.java:4821) [guava-17.0.jar:?]
at com.google.common.cache.LocalCache$LocalLoadingCache.getUnchecked(LocalCache.java:4827) [guava-17.0.jar:?]
at com.mojang.authlib.yggdrasil.YggdrasilMinecraftSessionService.fillProfileProperties(YggdrasilMinecraftSessionService.java:148) [YggdrasilMinecraftSessionService.class:?]
at net.minecraft.client.resources.SkinManager$3.run(SkinManager.java:138) [skinManager$3.class:?]
at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511) [?:1.8.0_05]
at java.util.concurrent.FutureTask.run(FutureTask.java:266) [?:1.8.0_05]
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142) [?:1.8.0_05]
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617) [?:1.8.0_05]
at java.lang.Thread.run(Thread.java:745) [?:1.8.0_05]

 

The world still loads fine when in the dev environment but when I try building it and using it outside the dev environment it just refuses to create the world. Is it something to do with packets or something else?

Short answer: Nothing to worry about.

 

Long answer:Nothing to worry about. It's just that the client can't authorize the username of the Dev environment which is usually Player[random number] so it doesn't actually exist on the mojang servers and it returns the authorization error telling you, you can't play on online servers

The issue is though, it won't let me play at all as when I create the world I get sent back to the main menu.