Concurrent error

[GeorgeRNG]

Describe the bug A clear and concise description of what the bug is.

To Reproduce Steps to reproduce the behavior:

1. Enter dev mode

Expected behavior No crash

Screenshots //[16:58:44] [Netty Epoll Client IO #4/INFO] (Minecraft) [STDERR]: at net.minecraft.world.World.getBlockEntity(World.java:577) //[16:58:44] [Netty Epoll Client IO #4/INFO] (Minecraft) [STDERR]: at dev.dfonline.codeclient.CodeClient.handlePacket(CodeClient.java:79)

Checks Please check all these for more infomation with the bug.

• [x] I am using the latest version.
• [x] I have tried disabling various options to see if they cause the issue, such as new ones or ones I have recently enabled.