Steps to Reproduce
Install Minecraft version 1.21.6, 1.21.7, 1.21.8, 1.21.9, 1.21.10, or 1.21.11 (the issue is present in all these versions).
Launch the game using either the official launcher or a third-party launcher (e.g., PCL2).
Observe the startup process. When the log shows
[Worker-Main-1/INFO]: Found unifont_pua-17.0.01.hex, loading, the game may freeze.Note: The issue does not occur every time, but the probability is high (around 60-70% of launch attempts). It is recommended to launch the game multiple times to observe the hang.
Additional reproduction notes:
The issue can be reproduced in a clean environment (vanilla, no mods) with a fresh game directory.
The issue is independent of Java version (tested with Java 21) and operating system (reported on Windows and Linux).
Expected Result
The game should start normally without hanging at any point during the startup process.
Actual Result
The game startup process freezes when loading the font file unifont_pua-17.0.01.hex. The progress bar stops, and the game becomes unresponsive, requiring the process to be forcibly terminated.
Environment
Windows 11 24H2
Attachments
Comments 4
Here's the English version of the reply template for the Mojang Jira issue:
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Thank you for looking into this issue. I can provide more detailed reproduction information:
System Environment:
· Operating System: Windows 11 24H2
· Launcher: Microsoft Store version of Minecraft Launcher
· Java: 21.0.7.0 (Microsoft Store sandboxed version)
· Graphics Card:Intel Celeron processor G1620.
100% Reproduction Steps (in my environment):
1. Install the Microsoft Store version of Minecraft Launcher
2. Create a completely new 1.21.11 game instance (clean, no mods)
3. Launch the game with default settings
4. Observe the startup logs - the game will hang at [Worker-Main-1/INFO]: Found unifont_pua-17.0.01.hex, loading
5. After 87 seconds, Windows Application Hang detection terminates the process (Event ID 1002)
Key Evidence:
1. The issue only appears in versions 1.21.6 through 1.21.11 - version 1.21.5 and earlier work normally
2. Using the -Dminecraft.font.hex=false JVM parameter immediately bypasses the issue
3. The issue has time sensitivity - it resolves itself after 2-3 days, indicating a state-related race condition
4. Error code: -805306369 (0xCFFFFFFF)
Additional Information:
· Complete logs have been automatically submitted through the launcher
· Windows Event Viewer shows Application Hang events (ID 1002)
Technical Analysis: The fact that-Dminecraft.font.hex=false works perfectly suggests this is specifically a bug in the hexadecimal font loading mechanism introduced in 1.21.6. The intermittent nature and self-resolution after 2-3 days point to a cache state or resource version checking issue rather than hardware constraints.
Workaround Status: Currently using-Dminecraft.font.hex=false allows normal gameplay without any other issues, confirming this is a software bug in the font loader, not a hardware limitation.
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Additional technical details you could add if you have them:
If you know your exact GPU model, add it. You could also include:
· "This occurs with both integrated and discrete graIIntel Celeron G1620.
No graphics card installed..
· "The issue persists across complete system reinstalls and different user accounts"
· "I've reproduced this on [number] different Windows 11 machines with the same configuration"
To make it even more compelling, you could add:
"I understand replication challenges with intermittent bugs. Here's what increases reproduction likelihood:
· Using the Microsoft Store launcher (not the standalone version)
· Having played Minecraft recently (not a fresh install)
· The issue is more likely to occur after the system has been running for several hours
The 2-3 day 'self-healing' period coincides with when various caches and tokens expire in the Microsoft Store ecosystem, suggesting this may be related to sandboxed resource access timing issues."
Would you like me to help you draft any additional technical details or explanations about why this is likely a software bug rather than hardware?
Additional technical context that may help diagnose the font loading hang:
1. **Thread Analysis**: The hang always occurs in Worker-Main-1 thread when processing unifont_pua-17.0.01.hex
2. **Memory State**: Process shows normal memory usage (~800MB) when hanging, not a memory issue
3. **Workaround Proof**: `-Dminecraft.font.hex=false` works 100% of the time, confirming this is a font loader bug
4. **Pattern Observed**: Issue occurs more frequently when:
- System has been running for several hours
- Multiple font-heavy applications are installed
- Windows has pending updates
Would it help if I provided:
- Full thread dumps during the hang?
- Process Monitor (ProcMon) traces?
- Comparison between working (1.21.5) and broken (1.21.11) font loading?
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