ShadowofElements

Thank you for your time.

Sorry about that Kumasasa. It truly is my fault. By the way, this issue is fixed in Java 9 Build 42 that just came out.

I found the solution. I had Java SE Development Kit 9 installed, and Minecraft was using that version. The issue is with Java 9 Build 39, so I uninstalled all of my Java 9 versions. Now I have Java 8 Build 25 installed, and copy and paste works fine.

I downgraded to Java 8 Update 25 and the issue is still present.

Here is a screenshot of the issue. I will try downgrading.

Thanks Mojang!

This should be one of the highest priority bugs in 1.8, as it causes a lot of lag for many maps and superflat worlds. A lot of players will complain about the new found lag in certain situations, so this bug should be fixed ASAP. Please help us, Mojang

I REALLY hope that this bug gets released in a map maker update. This will cause a lot of frustration, and @Samg_is_a_Ninja, you are right. This bug wouldn't take barely any effort at all to fix. Please Mojang, help us!

This is a duplicate of this bug:
https://bugs.mojang.com/browse/MC-58120

Setting the gamerule doMobSpawning to false removes a lot of the performance issues. Also, here is a video of the issue:
https://www.youtube.com/watch?v=kOxq3RhIOyw
The issue is strongest in open air worlds or a superflat world with the setting 3;minecraft:barrier;1;

It seems that setting the gamerule doMobSpawning to false removes a lot of the performance issues. This could help in finding the cause of this bug.

The video I recorded is up. Here is the link: https://www.youtube.com/watch?v=kOxq3RhIOyw

8. I will try lowering it, if that is what you are suggesting.

Edit: I lowered it to 2, and nothing changed.

Crash log for 14w30b attached.

@Samg_is_a_Ninja I don't believe that is the reason. The problem occurs in the map that I made when a player gets close enough to an air chunk to try and populate it, which means to add the decorations and such. Because I have air chunks in a normal world, this crash occurs when the game tries to populate them. I tried pre-generating the chunks, but to no avail.

@Samg_is_a_Ninja I understand that it will apply until it is fixed, but I am trying to keep this bug updated as it is very important to certain custom maps (including the one I am trying to create).

...and 14w29b. Crash log attached.

This bug still occurs in snapshot 14w29a. I attached the crash log.

I have also been having this issue creating a custom map of mine. I create a void area by creating a super flat world with the generation settings 2;0;1. I then changed the world type of the single player world using no 3rd party software, and the "n must be positive" crash occurs every time I join the world. It has halted my progress on the map, making this update a pretty unsuccessful "map maker" update. A fix would be very appreciated.