The game can crash due to certain race conditions in multiplayer

Minecraft can crash in race certain conditions in multiplayer mode

Description: The debug-screen entry list is exposed by reference and iterated with a fail-fast iterator while it can be structurally rebuilt at the same time.

• DebugScreenEntryList#getCurrentlyEnabled() returns the internal ArrayList directly (no defensive copy).

• DebugScreenOverlay#extractRenderState() iterates that list with a for-each during render-state extraction.

• DebugScreenEntryList#rebuildCurrentList() does clear() + add() + sort() on the same list. It is triggered by toggling the overlay (F3 / the F3 chart shortcuts), the reducedDebugInfo option, and LocalPlayer#setReducedDebugInfo() from server packets (login/abilities). When a rebuild lands during the extract iteration, the iterator throws ConcurrentModificationException and the client crashes.