steps to reproduce

1. boot game with fabric and wildfires female gender mod installed

2. load a single-player world

.3 press g click and change the gender to female or other

4. click appearance settings and crash

crash log

---- Minecraft Crash Report ----
// You're mean.

Time: 2024-05-08 12:20:14
Description: mouseClicked event handler

java.lang.IncompatibleClassChangeError: class com.wildfire.gui.WildfireBreastPresetList overrides final method net.minecraft.class_339.method_37020(Lnet/minecraft/class_6382;)V
at java.base/java.lang.ClassLoader.defineClass1(Native Method)
at java.base/java.lang.ClassLoader.defineClass(ClassLoader.java:1017)
at java.base/java.security.SecureClassLoader.defineClass(SecureClassLoader.java:150)
at net.fabricmc.loader.impl.launch.knot.KnotClassLoader.defineClassFwd(KnotClassLoader.java:160)
at net.fabricmc.loader.impl.launch.knot.KnotClassDelegate.tryLoadClass(KnotClassDelegate.java:355)
at net.fabricmc.loader.impl.launch.knot.KnotClassDelegate.loadClass(KnotClassDelegate.java:218)
at net.fabricmc.loader.impl.launch.knot.KnotClassLoader.loadClass(KnotClassLoader.java:119)
at java.base/java.lang.ClassLoader.loadClass(ClassLoader.java:525)
at com.wildfire.gui.screen.WildfireBreastCustomizationScreen.method_25426(WildfireBreastCustomizationScreen.java:133)
at net.minecraft.class_437.method_25423(class_437.java:298)
at net.minecraft.class_310.method_1507(class_310.java:1187)
at com.wildfire.gui.screen.WardrobeBrowserScreen.lambda$init$1(WardrobeBrowserScreen.java:76)
at net.minecraft.class_4185.method_25306(class_4185.java:95)
at net.minecraft.class_4264.method_25348(class_4264.java:48)
at net.minecraft.class_339.method_25402(class_339.java:145)
at net.minecraft.class_4069.method_25402(class_4069.java:38)
at net.minecraft.class_312.method_1611(class_312.java:99)
at net.minecraft.class_437.method_25412(class_437.java:414)
at net.minecraft.class_312.method_1601(class_312.java:99)
at net.minecraft.class_312.method_22686(class_312.java:180)
at net.minecraft.class_1255.execute(class_1255.java:102)
at net.minecraft.class_312.method_22684(class_312.java:180)
at org.lwjgl.glfw.GLFWMouseButtonCallbackI.callback(GLFWMouseButtonCallbackI.java:43)
at org.lwjgl.system.JNI.invokeV(Native Method)
at org.lwjgl.glfw.GLFW.glfwPollEvents(GLFW.java:3438)
at com.mojang.blaze3d.systems.RenderSystem.pollEvents(RenderSystem.java:202)
at com.mojang.blaze3d.systems.RenderSystem.flipFrame(RenderSystem.java:220)
at net.minecraft.class_1041.method_15998(class_1041.java:287)
at net.minecraft.class_310.method_1523(class_310.java:1349)
at net.minecraft.class_310.method_1514(class_310.java:888)
at net.minecraft.client.main.Main.main(Main.java:265)
at net.fabricmc.loader.impl.game.minecraft.MinecraftGameProvider.launch(MinecraftGameProvider.java:470)
at net.fabricmc.loader.impl.launch.knot.Knot.launch(Knot.java:74)
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 java.base/java.lang.ClassLoader.defineClass1(Native Method)
at java.base/java.lang.ClassLoader.defineClass(ClassLoader.java:1017)
at java.base/java.security.SecureClassLoader.defineClass(SecureClassLoader.java:150)
at net.fabricmc.loader.impl.launch.knot.KnotClassLoader.defineClassFwd(KnotClassLoader.java:160)
at net.fabricmc.loader.impl.launch.knot.KnotClassDelegate.tryLoadClass(KnotClassDelegate.java:355)
at net.fabricmc.loader.impl.launch.knot.KnotClassDelegate.loadClass(KnotClassDelegate.java:218)
at net.fabricmc.loader.impl.launch.knot.KnotClassLoader.loadClass(KnotClassLoader.java:119)
at java.base/java.lang.ClassLoader.loadClass(ClassLoader.java:525)
at com.wildfire.gui.screen.WildfireBreastCustomizationScreen.method_25426(WildfireBreastCustomizationScreen.java:133)
at net.minecraft.class_437.method_25423(class_437.java:298)
at net.minecraft.class_310.method_1507(class_310.java:1187)
at com.wildfire.gui.screen.WardrobeBrowserScreen.lambda$init$1(WardrobeBrowserScreen.java:76)
at net.minecraft.class_4185.method_25306(class_4185.java:95)
at net.minecraft.class_4264.method_25348(class_4264.java:48)
at net.minecraft.class_339.method_25402(class_339.java:145)
at net.minecraft.class_4069.method_25402(class_4069.java:38)
at net.minecraft.class_312.method_1611(class_312.java:99)

-- Affected screen --
Details:
Screen name: com.wildfire.gui.screen.WardrobeBrowserScreen
Stacktrace:
at net.minecraft.class_437.method_25412(class_437.java:414)
at net.minecraft.class_312.method_1601(class_312.java:99)
at net.minecraft.class_312.method_22686(class_312.java:180)
at net.minecraft.class_1255.execute(class_1255.java:102)
at net.minecraft.class_312.method_22684(class_312.java:180)
at org.lwjgl.glfw.GLFWMouseButtonCallbackI.callback(GLFWMouseButtonCallbackI.java:43)
at org.lwjgl.system.JNI.invokeV(Native Method)
at org.lwjgl.glfw.GLFW.glfwPollEvents(GLFW.java:3438)
at com.mojang.blaze3d.systems.RenderSystem.pollEvents(RenderSystem.java:202)
at com.mojang.blaze3d.systems.RenderSystem.flipFrame(RenderSystem.java:220)
at net.minecraft.class_1041.method_15998(class_1041.java:287)
at net.minecraft.class_310.method_1523(class_310.java:1349)
at net.minecraft.class_310.method_1514(class_310.java:888)
at net.minecraft.client.main.Main.main(Main.java:265)
at net.fabricmc.loader.impl.game.minecraft.MinecraftGameProvider.launch(MinecraftGameProvider.java:470)
at net.fabricmc.loader.impl.launch.knot.Knot.launch(Knot.java:74)
at net.fabricmc.loader.impl.launch.knot.KnotClient.main(KnotClient.java:23)

-- System Details --
Details:
Minecraft Version: 1.20.4
Minecraft Version ID: 1.20.4
Operating System: Windows 11 (amd64) version 10.0
Java Version: 17.0.8, Microsoft
Java VM Version: OpenJDK 64-Bit Server VM (mixed mode), Microsoft
Memory: 815410424 bytes (777 MiB) / 2254438400 bytes (2150 MiB) up to 4294967296 bytes (4096 MiB)
CPUs: 12
Processor Vendor: GenuineIntel
Processor Name: Intel(R) Core(TM) i5-10400F CPU @ 2.90GHz
Identifier: Intel64 Family 6 Model 165 Stepping 3
Microarchitecture: unknown
Frequency (GHz): 2.90
Number of physical packages: 1
Number of physical CPUs: 6
Number of logical CPUs: 12
Graphics card #0 name: AMD Radeon RX 6600
Graphics card #0 vendor: Advanced Micro Devices, Inc. (0x1002)
Graphics card #0 VRAM (MB): 4095.00
Graphics card #0 deviceId: 0x73ff
Graphics card #0 versionInfo: DriverVersion=31.0.24002.92
Memory slot #0 capacity (MB): 8192.00
Memory slot #0 clockSpeed (GHz): 2.40
Memory slot #0 type: DDR4
Memory slot #1 capacity (MB): 8192.00
Memory slot #1 clockSpeed (GHz): 2.40
Memory slot #1 type: DDR4
Virtual memory max (MB): 29623.67
Virtual memory used (MB): 19859.84
Swap memory total (MB): 13312.00
Swap memory used (MB): 1694.19
JVM Flags: 4 total; -XX:HeapDumpPath=MojangTricksIntelDriversForPerformance_javaw.exe_minecraft.exe.heapdump -Xss1M -Xmx4096m -Xms256m
Fabric Mods:
cheatdetector: CheatDetector 1.1.5.1
cloth-config: Cloth Config v13 13.0.121
cloth-basic-math: cloth-basic-math 0.6.1
entityculling: EntityCulling 1.6.4
exordium: Exordium 1.2.1
fabric-api: Fabric API 0.97.0+1.20.4
fabric-api-base: Fabric API Base 0.4.37+78d798af4f
fabric-api-lookup-api-v1: Fabric API Lookup API (v1) 1.6.50+82b1bb3e4f
fabric-biome-api-v1: Fabric Biome API (v1) 13.0.17+78d798af4f
fabric-block-api-v1: Fabric Block API (v1) 1.0.17+3e2216cb4f
fabric-block-view-api-v2: Fabric BlockView API (v2) 1.0.5+78d798af4f
fabric-blockrenderlayer-v1: Fabric BlockRenderLayer Registration (v1) 1.1.47+78d798af4f
fabric-client-tags-api-v1: Fabric Client Tags 1.1.8+78d798af4f
fabric-command-api-v1: Fabric Command API (v1) 1.2.42+f71b366f4f
fabric-command-api-v2: Fabric Command API (v2) 2.2.21+78d798af4f
fabric-commands-v0: Fabric Commands (v0) 0.2.59+df3654b34f
fabric-containers-v0: Fabric Containers (v0) 0.1.87+df3654b34f
fabric-content-registries-v0: Fabric Content Registries (v0) 5.0.16+78d798af4f
fabric-convention-tags-v1: Fabric Convention Tags 1.5.11+78d798af4f
fabric-crash-report-info-v1: Fabric Crash Report Info (v1) 0.2.24+78d798af4f
fabric-data-attachment-api-v1: Fabric Data Attachment API (v1) 1.1.5+b90db5744f
fabric-data-generation-api-v1: Fabric Data Generation API (v1) 13.2.5+5c0133444f
fabric-dimensions-v1: Fabric Dimensions API (v1) 2.1.62+78d798af4f
fabric-entity-events-v1: Fabric Entity Events (v1) 1.6.2+09fc25014f
fabric-events-interaction-v0: Fabric Events Interaction (v0) 0.7.2+389931eb4f
fabric-events-lifecycle-v0: Fabric Events Lifecycle (v0) 0.2.75+df3654b34f
fabric-game-rule-api-v1: Fabric Game Rule API (v1) 1.0.47+78d798af4f
fabric-item-api-v1: Fabric Item API (v1) 2.3.0+bcdd12964f
fabric-item-group-api-v1: Fabric Item Group API (v1) 4.0.27+ee30b13a4f
fabric-key-binding-api-v1: Fabric Key Binding API (v1) 1.0.42+78d798af4f
fabric-keybindings-v0: Fabric Key Bindings (v0) 0.2.40+df3654b34f
fabric-lifecycle-events-v1: Fabric Lifecycle Events (v1) 2.3.1+a67ffb5d4f
fabric-loot-api-v2: Fabric Loot API (v2) 2.1.10+78d798af4f
fabric-message-api-v1: Fabric Message API (v1) 6.0.6+78d798af4f
fabric-mining-level-api-v1: Fabric Mining Level API (v1) 2.1.66+78d798af4f
fabric-model-loading-api-v1: Fabric Model Loading API (v1) 1.0.9+78d798af4f
fabric-models-v0: Fabric Models (v0) 0.4.8+9386d8a74f
fabric-networking-api-v1: Fabric Networking API (v1) 3.1.8+2e5ac5484f
fabric-object-builder-api-v1: Fabric Object Builder API (v1) 13.1.0+dba1195c4f
fabric-particles-v1: Fabric Particles (v1) 1.1.8+78d798af4f
fabric-recipe-api-v1: Fabric Recipe API (v1) 2.0.21+78d798af4f
fabric-registry-sync-v0: Fabric Registry Sync (v0) 4.0.20+ee30b13a4f
fabric-renderer-api-v1: Fabric Renderer API (v1) 3.2.5+78d798af4f
fabric-renderer-indigo: Fabric Renderer - Indigo 1.5.5+78d798af4f
fabric-renderer-registries-v1: Fabric Renderer Registries (v1) 3.2.54+df3654b34f
fabric-rendering-data-attachment-v1: Fabric Rendering Data Attachment (v1) 0.3.43+73761d2e4f
fabric-rendering-fluids-v1: Fabric Rendering Fluids (v1) 3.1.2+e761c6694f
fabric-rendering-v0: Fabric Rendering (v0) 1.1.57+df3654b34f
fabric-rendering-v1: Fabric Rendering (v1) 3.2.1+6fd945a04f
fabric-resource-conditions-api-v1: Fabric Resource Conditions API (v1) 2.3.15+78d798af4f
fabric-resource-loader-v0: Fabric Resource Loader (v0) 0.11.21+ee30b13a4f
fabric-screen-api-v1: Fabric Screen API (v1) 2.0.18+78d798af4f
fabric-screen-handler-api-v1: Fabric Screen Handler API (v1) 1.3.56+78d798af4f
fabric-sound-api-v1: Fabric Sound API (v1) 1.0.18+78d798af4f
fabric-transfer-api-v1: Fabric Transfer API (v1) 4.0.12+90f2d7b14f
fabric-transitive-access-wideners-v1: Fabric Transitive Access Wideners (v1) 5.0.15+78d798af4f
fabric-language-kotlin: Fabric Language Kotlin 1.10.19+kotlin.1.9.23
org_jetbrains_kotlin_kotlin-reflect: kotlin-reflect 1.9.23
org_jetbrains_kotlin_kotlin-stdlib: kotlin-stdlib 1.9.23
org_jetbrains_kotlin_kotlin-stdlib-jdk7: kotlin-stdlib-jdk7 1.9.23
org_jetbrains_kotlin_kotlin-stdlib-jdk8: kotlin-stdlib-jdk8 1.9.23
org_jetbrains_kotlinx_atomicfu-jvm: atomicfu-jvm 0.23.2
org_jetbrains_kotlinx_kotlinx-coroutines-core-jvm: kotlinx-coroutines-core-jvm 1.8.0
org_jetbrains_kotlinx_kotlinx-coroutines-jdk8: kotlinx-coroutines-jdk8 1.8.0
org_jetbrains_kotlinx_kotlinx-datetime-jvm: kotlinx-datetime-jvm 0.5.0
org_jetbrains_kotlinx_kotlinx-serialization-cbor-jvm: kotlinx-serialization-cbor-jvm 1.6.3
org_jetbrains_kotlinx_kotlinx-serialization-core-jvm: kotlinx-serialization-core-jvm 1.6.3
org_jetbrains_kotlinx_kotlinx-serialization-json-jvm: kotlinx-serialization-json-jvm 1.6.3
fabricloader: Fabric Loader 0.15.10
mixinextras: MixinExtras 0.3.5
firstperson: FirstPerson 2.3.4
immediatelyfast: ImmediatelyFast 1.2.14+1.20.4
net_lenni0451_reflect: Reflect 1.3.2
iris: Iris 1.7.0+mc1.20.4
io_github_douira_glsl-transformer: glsl-transformer 2.0.0-pre13
org_anarres_jcpp: jcpp 1.4.14
org_antlr_antlr4-runtime: antlr4-runtime 4.11.1
java: OpenJDK 64-Bit Server VM 17
minecraft: Minecraft 1.20.4
modernfix: ModernFix 5.17.0+mc1.20.4
modmenu: Mod Menu 9.0.0
mousetweaks: Mouse Tweaks 2.26
notenoughanimations: NotEnoughAnimations 1.7.3
notenoughcrashes: Not Enough Crashes 4.4.7+1.20.4
skinlayers3d: 3d-Skin-Layers 1.6.4
sodium: Sodium 0.5.8+mc1.20.4
sodium-extra: Sodium Extra 0.5.4+mc1.20.4-build.116
caffeineconfig: CaffeineConfig 1.3.0+1.17
crowdin-translate: CrowdinTranslate 1.4+1.19.3
wildfire_gender: Wildfire's Female Gender Mod 1.20.2-3.2.1
Loaded Shaderpack: (off)
Client Crashes Since Restart: 1
Integrated Server Crashes Since Restart: 0
Suspected Mods: Wildfire's Female Gender Mod (wildfire_gender), Minecraft (minecraft), Fabric Loader (fabricloader)

An official version of the mod for 1.20.4 isn't out on CurseForge or Modrinth yet since Wildfire hasn't been too active, but someone from the Discord made a jar for 1.20.4. (If you'd like that you can either find it in the #mod-discussion channels pins on the Discord, or download it here (temp link, thanks Discord)
Not really sure when Wildfire will return, but all we can do for now is wait
Alternatively, you can also compile the mod yourself since there is actually a branch for 1.20.4 Fabric