Access Violation / Illegal instruction - Frequent client crashes observed without clear root cause, even on vanilla worlds.

Partner Rank: Critical

Verification Builds: 1.21.41 (28695439)

Regression Builds: Unknown

Summary: Frequent client crashes observed without clear root cause, even on vanilla worlds.

Affects currently Live Content: No

Impact: Players may experience frequent crashes, disrupting gameplay across multiple devices and environments. Makes it difficult to develop content when the client is crashing so often. Attempted a clean installation to no avail.

Repro Steps:

1. Launch Minecraft Bedrock Edition 1.21.41.
2. Load into any vanilla world (without any resource or behavior packs).
3. Move around the world without performing any specific actions. You might find flying around with noclip produces a crash sooner.
4. Observe for a potential crash within a few minutes of general movement.

Observed Results: The client crashes unexpectedly while moving around in a vanilla world. Attaching to WinDbg yields "Access Violation" and "Issue: Illegal instruction - code c000001d Minecraft_Windows+0x6a29f0f". We are seeing this crash across multiple machines, even when we aren't using any custom content, but the repro is very inconsistent.

Expected Results: The client should run smoothly without crashes during normal gameplay in a vanilla world.

Screenshots/Videos attached: Yes ( https://capture.dropbox.com/nwddfT0qBtZnRe60 )

Notes:

• The video above is using a custom pack, but this bug happens on vanilla worlds too. But since repro is inconsistent, its the only video we have showing the issue.
• Logs in com.mojang do not contain crash information. A crash captured with WinDbg reveals the error code c000001d at MinecrafT_Windows+0x6a29f0f.
• Additional details and DxDiag report: https://gist.github.com/jamiechapman/02661ae009fe8a0c6412cc7ac093c142
• Event viewer log: