Iris Error with iris-fabric-1.9.6+mc1.21.9

What happened?

A bug happened!

Start the game, create a new world and when running it a message appears that says "Saving" and the game closes automatically. Apart from the mod iris-fabric-1.9.6+mc1.21.9 I am using the mod entity_texture_features-7.0.4-1.21.9-fabric and entity_model_features_1.21.9-fabric-3.0.3 which conflict and that is why it generates the error.

Screenshots

Log output

---- Minecraft Crash Report ---- // My bad.

Time: 2025-10-11 22:57:11 Description: Unexpected error

java.lang.NullPointerException: Cannot invoke "net.minecraft.class_746.method_31548()" because "this.field_3712.field_1724" is null at knot//net.minecraft.class_636.method_2911(class_636.java:308) at knot//net.minecraft.class_636.method_2927(class_636.java:291) at knot//net.minecraft.class_310.method_1574(class_310.java:1850) at knot//net.minecraft.class_310.method_1523(class_310.java:1345) at knot//net.minecraft.class_310.method_1514(class_310.java:969) at knot//net.minecraft.client.main.Main.main(Main.java:250) at net.fabricmc.loader.impl.game.minecraft.MinecraftGameProvider.launch(MinecraftGameProvider.java:506) at net.fabricmc.loader.impl.launch.knot.Knot.launch(Knot.java:72) at net.fabricmc.loader.impl.launch.knot.KnotClient.main(KnotClient.java:23)

A detailed walkthrough of the error, its code path and all known details is as follows:

-- Head -- Thread: Render thread Stacktrace: at knot//net.minecraft.class_636.method_2911(class_636.java:308) at knot//net.minecraft.class_636.method_2927(class_636.java:291)

-- Uptime -- Details: JVM uptime: 40.612s Wall uptime: 28.919s High-res time: 27.258s Client ticks: 363 ticks / 18.150s Stacktrace: at knot//net.minecraft.class_310.method_1587(class_310.java:2434) at knot//net.minecraft.class_310.method_54580(class_310.java:1038) at knot//net.minecraft.class_310.method_1514(class_310.java:993) at knot//net.minecraft.client.main.Main.main(Main.java:250) at net.fabricmc.loader.impl.game.minecraft.MinecraftGameProvider.launch(MinecraftGameProvider.java:506) at net.fabricmc.loader.impl.launch.knot.Knot.launch(Knot.java:72) at net.fabricmc.loader.impl.launch.knot.KnotClient.main(KnotClient.java:23)

-- Affected level -- Details: All players: 0 total; Chunk stats: 729, 0 Level dimension: minecraft:overworld Level spawn location: World: (8,64,8), Section: (at 8,0,8 in 0,4,0; chunk contains blocks 0,-64,0 to 15,319,15), Region: (0,0; contains chunks 0,0 to 31,31, blocks 0,-64,0 to 511,319,511) Level time: 0 game time, 0 day time Server brand: ~~ERROR~~ NullPointerException: Cannot read field "field_3944" because "this.field_3729.field_1724" is null Server type: Integrated singleplayer server Tracked entity count: 0

-- Last reload -- Details: Reload number: 1 Reload reason: initial Finished: Yes Packs: vanilla, fabric, ambientsounds, creativecore, entity_model_features, entity_texture_features, fabric-api, fabric-api-base, fabric-api-lookup-api-v1, fabric-biome-api-v1, fabric-block-api-v1, fabric-block-view-api-v2, fabric-command-api-v2, fabric-content-registries-v0, fabric-convention-tags-v1, fabric-convention-tags-v2, fabric-crash-report-info-v1, fabric-data-attachment-api-v1, fabric-data-generation-api-v1, fabric-dimensions-v1, fabric-entity-events-v1, fabric-events-interaction-v0, fabric-game-rule-api-v1, fabric-item-api-v1, fabric-item-group-api-v1, fabric-key-binding-api-v1, fabric-lifecycle-events-v1, fabric-loot-api-v2, fabric-loot-api-v3, fabric-message-api-v1, fabric-model-loading-api-v1, fabric-networking-api-v1, fabric-object-builder-api-v1, fabric-particles-v1, fabric-recipe-api-v1, fabric-registry-sync-v0, fabric-renderer-api-v1, fabric-renderer-indigo, fabric-rendering-fluids-v1, fabric-rendering-v1, fabric-resource-conditions-api-v1, fabric-resource-loader-v0, fabric-resource-loader-v1, fabric-screen-api-v1, fabric-screen-handler-api-v1, fabric-serialization-api-v1, fabric-sound-api-v1, fabric-tag-api-v1, fabric-transfer-api-v1, fabric-transitive-access-wideners-v1, fabricloader, iris, lithium, modmenu, placeholder-api, sodium, sound_physics_remastered, wi_zoom

-- System Details -- Details: Minecraft Version: 1.21.9 Minecraft Version ID: 1.21.9 Operating System: Windows 11 (amd64) version 10.0 Java Version: 21.0.7, Microsoft Java VM Version: OpenJDK 64-Bit Server VM (mixed mode), Microsoft Memory: 216825064 bytes (206 MiB) / 671088640 bytes (640 MiB) up to 2147483648 bytes (2048 MiB) CPUs: 24 Processor Vendor: AuthenticAMD Processor Name: AMD Ryzen 9 5900X 12-Core Processor
Identifier: AuthenticAMD Family 25 Model 33 Stepping 2 Microarchitecture: Zen 3 Frequency (GHz): 3.70 Number of physical packages: 1 Number of physical CPUs: 12 Number of logical CPUs: 24 Graphics card #0 name: NVIDIA GeForce RTX 4070 Graphics card #0 vendor: NVIDIA Graphics card #0 VRAM (MiB): 12282.00 Graphics card #0 deviceId: VideoController1 Graphics card #0 versionInfo: 32.0.15.8097 Memory slot #0 capacity (MiB): 16384.00 Memory slot #0 clockSpeed (GHz): 3.60 Memory slot #0 type: DDR4 Memory slot #1 capacity (MiB): 16384.00 Memory slot #1 clockSpeed (GHz): 3.60 Memory slot #1 type: DDR4 Virtual memory max (MiB): 34741.31 Virtual memory used (MiB): 19570.74 Swap memory total (MiB): 2048.00 Swap memory used (MiB): 83.55 Space in storage for jna.tmpdir (MiB): available: 160434.56, total: 475955.00 Space in storage for org.lwjgl.system.SharedLibraryExtractPath (MiB): available: 160434.56, total: 475955.00 Space in storage for io.netty.native.workdir (MiB): available: 160434.56, total: 475955.00 Space in storage for java.io.tmpdir (MiB): available: 160434.56, total: 475955.00 Space in storage for workdir (MiB): available: 160434.56, total: 475955.00 JVM Flags: 9 total; -XX:HeapDumpPath=MojangTricksIntelDriversForPerformance_javaw.exe_minecraft.exe.heapdump -Xss1M -Xmx2G -XX:+UnlockExperimentalVMOptions -XX:+UseG1GC -XX:G1NewSizePercent=20 -XX:G1ReservePercent=20 -XX:MaxGCPauseMillis=50 -XX:G1HeapRegionSize=32M Debug Flags: 0 total; Fabric Mods: ambientsounds: AmbientSounds 6.2.2 creativecore: CreativeCore 2.14.7 net_neoforged_bus: bus 7.2.0 entity_model_features: Entity Model Features 3.0.3 entity_texture_features: Entity Texture Features 7.0.4 org_apache_httpcomponents_httpmime: httpmime 4.5.10 fabric-api: Fabric API 0.134.0+1.21.9 fabric-api-base: Fabric API Base 1.0.0+14b92d897d fabric-api-lookup-api-v1: Fabric API Lookup API (v1) 1.6.106+d17682157d fabric-biome-api-v1: Fabric Biome API (v1) 16.1.0+c2417d4f7d fabric-block-api-v1: Fabric Block API (v1) 1.1.5+d17682157d fabric-block-view-api-v2: Fabric BlockView API (v2) 1.0.34+e4fd1b927d fabric-command-api-v2: Fabric Command API (v2) 2.3.7+328a75ba7d fabric-content-registries-v0: Fabric Content Registries (v0) 10.2.3+b6a242647d fabric-convention-tags-v1: Fabric Convention Tags 2.1.47+7f945d5b7d fabric-convention-tags-v2: Fabric Convention Tags (v2) 2.15.12+3154c1c87d fabric-crash-report-info-v1: Fabric Crash Report Info (v1) 0.3.18+33df5e6e7d fabric-data-attachment-api-v1: Fabric Data Attachment API (v1) 1.8.28+9bce411b7d fabric-data-generation-api-v1: Fabric Data Generation API (v1) 23.2.22+d8b85ef17d fabric-dimensions-v1: Fabric Dimensions API (v1) 4.0.22+38b9cc197d fabric-entity-events-v1: Fabric Entity Events (v1) 2.1.12+14b92d897d fabric-events-interaction-v0: Fabric Events Interaction (v0) 4.0.35+5ba217127d fabric-game-rule-api-v1: Fabric Game Rule API (v1) 1.1.1+e47eaae57d fabric-item-api-v1: Fabric Item API (v1) 11.5.8+9bce411b7d fabric-item-group-api-v1: Fabric Item Group API (v1) 4.2.24+86b3ae577d fabric-key-binding-api-v1: Fabric Key Binding API (v1) 1.1.1+b3ba9c487d fabric-lifecycle-events-v1: Fabric Lifecycle Events (v1) 2.6.9+33df5e6e7d fabric-loot-api-v2: Fabric Loot API (v2) 3.0.64+3f89f5a57d fabric-loot-api-v3: Fabric Loot API (v3) 2.0.11+d17682157d fabric-message-api-v1: Fabric Message API (v1) 6.1.7+3154c1c87d fabric-model-loading-api-v1: Fabric Model Loading API (v1) 6.0.0+3ffd6ef07d fabric-networking-api-v1: Fabric Networking API (v1) 5.0.13+d269470c7d fabric-object-builder-api-v1: Fabric Object Builder API (v1) 21.1.24+9bce411b7d fabric-particles-v1: Fabric Particles (v1) 4.2.2+a0ee59a47d fabric-recipe-api-v1: Fabric Recipe API (v1) 8.1.26+d17682157d fabric-registry-sync-v0: Fabric Registry Sync (v0) 6.1.41+679c8c5c7d fabric-renderer-api-v1: Fabric Renderer API (v1) 7.1.1+328a75ba7d fabric-renderer-indigo: Fabric Renderer - Indigo 4.0.19+328a75ba7d fabric-rendering-fluids-v1: Fabric Rendering Fluids (v1) 3.1.38+86b3ae577d fabric-rendering-v1: Fabric Rendering (v1) 16.0.1+328a75ba7d fabric-resource-conditions-api-v1: Fabric Resource Conditions API (v1) 5.0.28+33df5e6e7d fabric-resource-loader-v0: Fabric Resource Loader (v0) 3.2.2+3388a3b27d fabric-resource-loader-v1: Fabric Resource Loader (v1) 1.0.2+225bca407d fabric-screen-api-v1: Fabric Screen API (v1) 3.1.0+9c82a7987d fabric-screen-handler-api-v1: Fabric Screen Handler API (v1) 1.3.150+d17682157d fabric-serialization-api-v1: Fabric Serialization API (v1) 1.0.0+d857c9767d fabric-sound-api-v1: Fabric Sound API (v1) 1.0.45+328a75ba7d fabric-tag-api-v1: Fabric Tag API (v1) 1.2.10+2fa446b27d fabric-transfer-api-v1: Fabric Transfer API (v1) 6.0.15+79ec2c127d fabric-transitive-access-wideners-v1: Fabric Transitive Access Wideners (v1) 6.5.3+41eb43437d fabricloader: Fabric Loader 0.17.2 mixinextras: MixinExtras 0.5.0 iris: Iris 1.9.6+mc1.21.9 io_github_douira_glsl-transformer: glsl-transformer 3.0.0-pre3 org_anarres_jcpp: jcpp 1.4.14 org_antlr_antlr4-runtime: antlr4-runtime 4.13.1 java: OpenJDK 64-Bit Server VM 21 lithium: Lithium 0.19.1+mc1.21.9 minecraft: Minecraft 1.21.9 modmenu: Mod Menu 16.0.0-rc.1 placeholder-api: Placeholder API 2.8.0+1.21.9 sodium: Sodium 0.7.0+mc1.21.9 sound_physics_remastered: Sound Physics Remastered 1.21.9-1.5.1 wi_zoom: WI Zoom 1.6-MC1.21.9 Loaded Shaderpack: ComplementaryReimagined_r5.2.2.zip Profile: Custom (+19 options changed by user) Launched Version: fabric-loader-0.17.2-1.21.9 Launcher name: minecraft-launcher Backend library: LWJGL version 3.3.3-snapshot Backend API: NVIDIA GeForce RTX 4070/PCIe/SSE2 GL version 3.3.0 NVIDIA 580.97, NVIDIA Corporation Window size: 3440x1440 GFLW Platform: win32 Render Extensions: GL_ARB_buffer_storage, GL_KHR_debug, GL_ARB_vertex_attrib_binding, GL_ARB_direct_state_access GL debug messages: Is Modded: Definitely; Client brand changed to 'fabric'; Server brand changed to 'fabric' Universe: 400921fb54442d18 Type: Integrated Server (map_client.txt) Graphics mode: fancy Render Distance: 20/20 chunks Resource Packs: vanilla, fabric, ambientsounds (incompatible), creativecore (incompatible), entity_model_features (incompatible), entity_texture_features (incompatible), fabric-api, fabric-api-base, fabric-api-lookup-api-v1, fabric-biome-api-v1, fabric-block-api-v1, fabric-block-view-api-v2, fabric-command-api-v2, fabric-content-registries-v0, fabric-convention-tags-v1, fabric-convention-tags-v2, fabric-crash-report-info-v1, fabric-data-attachment-api-v1, fabric-data-generation-api-v1, fabric-dimensions-v1, fabric-entity-events-v1, fabric-events-interaction-v0, fabric-game-rule-api-v1, fabric-item-api-v1, fabric-item-group-api-v1, fabric-key-binding-api-v1, fabric-lifecycle-events-v1, fabric-loot-api-v2, fabric-loot-api-v3, fabric-message-api-v1, fabric-model-loading-api-v1, fabric-networking-api-v1, fabric-object-builder-api-v1, fabric-particles-v1, fabric-recipe-api-v1, fabric-registry-sync-v0, fabric-renderer-api-v1, fabric-renderer-indigo, fabric-rendering-fluids-v1, fabric-rendering-v1, fabric-resource-conditions-api-v1, fabric-resource-loader-v0, fabric-resource-loader-v1, fabric-screen-api-v1, fabric-screen-handler-api-v1, fabric-serialization-api-v1, fabric-sound-api-v1, fabric-tag-api-v1, fabric-transfer-api-v1, fabric-transitive-access-wideners-v1, fabricloader, iris, lithium, modmenu, placeholder-api, sodium, sound_physics_remastered, wi_zoom Current Language: es_mx Locale: es_CO System encoding: UTF-8 File encoding: UTF-8 CPU: 24x AMD Ryzen 9 5900X 12-Core Processor Server Running: true Player Count: 1 / 8; [class_3222['SerandreX'/238, l='ServerLevel[Natlan]', x=22.47, y=68.00, z=-66.75]] Active Data Packs: vanilla, fabric, fabric-convention-tags-v2 Available Data Packs: fabric, fabric-convention-tags-v2, minecart_improvements, redstone_experiments, trade_rebalance, vanilla Enabled Feature Flags: minecraft:vanilla World Generation: Stable World Seed: -9116938940048488739 Suppressed Exceptions: ~~NONE~~

crash-2025-10-11_22.57.11-client.txt