Adam Young

As MOD has mentioned, this is a 3rd party support issue.

However hint, .minecraft/server-resource-packs/ (it probably doesn't exist, as the error is indicating)

As previously posted by the mods, this is a technical support problem. JIRA (where you're posting) is for bug reports.

Reposting this isn't going to get you too far (just kind advice).

If you've installed Java8, open up a terminal, type 'whereis java' (no quotes), it should respond with /usr/bin/java. If you run '/usr/bin/java -version' it should give you something similar to:
java version "1.8.0_40"
Java(TM) SE Runtime Environment (build 1.8.0_40-b26)
Java HotSpot(TM) 64-Bit Server VM (build 25.40-b25, mixed mode)

Second, you have only allocated 1GB of memory when using a 512x512 texture pack. On the system you have, you will be getting around 5fps (if you're lucky). I only say this because I am running my MBP with 4GB dedicated to MC, on a Core i7, and it struggles to run 256x256 texture packs.

As the mod says, this is a technical support problem, but I would suggest changing the path to:

/usr/bin/java

and see if it continues to crash. I suspect that it won't (unless there is an underlying issue with hardware support).

@Peyton, in your game settings what is the path to the "java" binary?

It should be "/usr/bin/java" to use the proper Java8 installation as opposed to the default Java6 installed on OSX.

I was just commenting to say that I could confirm the same problem as the OP. Although... it would be great to see this get resolved/fixed at some point.

On a side note; I'm considering putting together an app that spawns a full-screen child process (similar to the MC Launcher + MC Game) and cycles through a bunch of calculations (to try some half-baked attempt at simulating a similar situation that we're seeing with Minecraft), then swapping into the alternate desktop and see if it does the same thing. I can't imagine that it will come up with anything too successful, but if I can replicate it like that, it would possibly point towards OSX and not MC.

Thanks for the replies John.

@John Dame I think we should probably preface the "default fullscreen" working part of this with a "may work, but unable to confirm". While in the in-game fullscreen, you can't switch to an alternate desktop, so it is entirely possible that the same thing could happen if you had the ability to switch when using the in-game fullscreen method.

Now.. the reason I still believe this to be Minecraft specific is due to the fact that ... the CPU spike doesn't happen at the title screen (I've tested this repeatedly) but it does happen when you've loaded a world. If this was an OS-level problem (or third party to Minecraft) it wouldn't matter whether you were on the title screen, in a world, creating a world, on a server, playing locally. For all intents and purposes, the OS should treat it all the same (now, I know technically... it isn't quite that simple but...)

There is something specific to MC when inside a world that is causing the spike when it loses focus and isn't viewable. (a perfect reason for this is... say a user wants to build a very difficult redstone build, needs to go back and forth between a tutorial and their own world. Their CPU would almost constantly sit at peak capacity making the experience unmanageable.)

Hey folks,

I've confirmed this happens on the latest OSX (Mavericks) running MC 1.8.x and Java8.

However, I've noticed that it only happens when you've loaded a world, if you're simply at the title screen the CPU does not spike. This is somehow tied directly to world processing, and only while not using the in-game fullscreen setting (using the OS-level fullscreen/"maximize").

If any additional information is required, please let me know and I will do what I can to gather it.