Describe the bug
A java.lang.NoSuchMethodError crash occurs when rendering entities (specifically FallingBlockEntity). It seems to be a compatibility issue between IrisFLW and the latest alpha versions of Iris and Sodium. The game crashes during the ModelBlockRenderer.tesselateBlock process as it fails to locate the beginBlock method in BlockSensitiveBufferBuilder.
To Reproduce
Steps to reproduce the behavior:
1.Cause a block (like sand or gravel) to fall due to gravity.
2.The game crashes immediately.
Desktop (please complete the following information):
MC version: 1.21.1
Iris version: iris-neoforge-1.8.13-snapshot+mc1.21.1
Sodium version: sodium-neoforge-0.8.12-alpha.4+mc1.21.1
IrisFlwCompat version: iris-flywheel-compat-NeoForge-2.4.0
GPU: GTX 1060 3GB
Additional context
The crash log indicates a conflict in ModelBlockRenderer mixins involving IrisFLW, Sodium, and other rendering-related mods. It appears that the recent changes in the alpha versions of Iris/Sodium may have changed or removed the method signature that IrisFLW relies on.
Crash log snippet:
java.lang.NoSuchMethodError: 'void net.irisshaders.iris.vertices.BlockSensitiveBufferBuilder.beginBlock(int, byte, byte, int, int, int)'
Attached is the full crash report for your reference.
*i use AI to analyze crash report because i dont have knowledge for this field. so i also use AI to write this bug report. if need more information to fix it. i can answer.
crash-2026-06-13_18.35.59-client.txt
Describe the bug
A java.lang.NoSuchMethodError crash occurs when rendering entities (specifically FallingBlockEntity). It seems to be a compatibility issue between IrisFLW and the latest alpha versions of Iris and Sodium. The game crashes during the ModelBlockRenderer.tesselateBlock process as it fails to locate the beginBlock method in BlockSensitiveBufferBuilder.
To Reproduce
Steps to reproduce the behavior:
1.Cause a block (like sand or gravel) to fall due to gravity.
2.The game crashes immediately.
Desktop (please complete the following information):
MC version: 1.21.1
Iris version: iris-neoforge-1.8.13-snapshot+mc1.21.1
Sodium version: sodium-neoforge-0.8.12-alpha.4+mc1.21.1
IrisFlwCompat version: iris-flywheel-compat-NeoForge-2.4.0
GPU: GTX 1060 3GB
Additional context
The crash log indicates a conflict in ModelBlockRenderer mixins involving IrisFLW, Sodium, and other rendering-related mods. It appears that the recent changes in the alpha versions of Iris/Sodium may have changed or removed the method signature that IrisFLW relies on.
Crash log snippet:
java.lang.NoSuchMethodError: 'void net.irisshaders.iris.vertices.BlockSensitiveBufferBuilder.beginBlock(int, byte, byte, int, int, int)'
Attached is the full crash report for your reference.
*i use AI to analyze crash report because i dont have knowledge for this field. so i also use AI to write this bug report. if need more information to fix it. i can answer.
crash-2026-06-13_18.35.59-client.txt