Crash on client shutdown

[0x484558]

WorldEdit Version

7.4.4 Beta 1

Platform Version

Fabric 0.19.3

Confirmations

• I am using the most recent Minecraft release.
• I am using a version of WorldEdit compatible with my Minecraft version.
• I am using the latest or recommended version of my platform software.
• I am NOT using a hybrid server, e.g. a server that combines Bukkit and Forge. Examples include Arclight, Mohist, and Cardboard.
• I am NOT using a fork of WorldEdit, such as FastAsyncWorldEdit (FAWE) or AsyncWorldEdit (AWE)

Bug Description

Minecraft 26.2 client (Fabric) errors out on shutdown. No other mods are involved, the error is reproducible with just WorldEdit alone and nothing else at all.

crash-2026-06-25_23.37.04-client.txt

Expected Behavior

The client must shutdown gracefully when closed.

Reproduction Steps

1. Run Minecraft 26.2 with Fabric until it reaches the main menu
2. Quit the game via the menu button

Anything Else?

No response

[TPO-Code]

I have the same bug.

This looks like a WorldEdit lifecycle bug, not a real gameplay crash.
WorldEdit starts a SessionManager at client startup. That manager creates a plain Java Timer named WorldEdit Session Manager. Plain Timer threads are non-daemon by default, so they keep the JVM alive unless explicitly canceled.

this is unlikely to cause any concerning issues,. It is just very annoying to get a popup 2 minuets after closing minecraft.

[me4502]

I have the same bug.

This looks like a WorldEdit lifecycle bug, not a real gameplay crash.
WorldEdit starts a SessionManager at client startup. That manager creates a plain Java Timer named WorldEdit Session Manager. Plain Timer threads are non-daemon by default, so they keep the JVM alive unless explicitly canceled.

this is unlikely to cause any concerning issues,. It is just very annoying to get a popup 2 minuets after closing minecraft.

See investigation here, #2975 (comment)

Making the timer thread a daemon in the past has caused widespread issue where the timer stops ticking, so it's not something we can safely just do, although I'm trialling it again to see if we get reports of it causing breakages.

This specific hang has been something reported for a while, but only in a very very tiny portion of the user base, which makes it the lesser of two issues when compared to the one that making the timer a daemon causes. A small subset of people are likely experiencing that one, and others experiencing the Vulkan bug I was able to reproduce in the above linked thread.

[me4502]

All the people I had test this (including myself) had the issue resolved by newer versions of the Fabric API. As the latest release now includes the latest Fabric API versions, this shouldn't happen anymore (unless something forces an old Fabric API version), so I'll close this.