---- Minecraft Crash Report ----
// This doesn't make any sense!

Time: 7/23/21, 4:36 PM
Description: Initializing game

java.lang.RuntimeException: Could not execute entrypoint stage 'main' due to errors, provided by 'megaweapons'!
at net.fabricmc.loader.entrypoint.minecraft.hooks.EntrypointUtils.invoke0(EntrypointUtils.java:50)
at net.fabricmc.loader.entrypoint.minecraft.hooks.EntrypointUtils.invoke(EntrypointUtils.java:33)
at net.fabricmc.loader.entrypoint.minecraft.hooks.EntrypointClient.start(EntrypointClient.java:33)
at net.minecraft.client.MinecraftClient.(MinecraftClient.java:518)
at net.minecraft.client.main.Main.main(Main.java:153)
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:78)
at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.base/java.lang.reflect.Method.invoke(Method.java:567)
at net.fabricmc.loader.game.MinecraftGameProvider.launch(MinecraftGameProvider.java:234)
at net.fabricmc.loader.launch.knot.Knot.launch(Knot.java:153)
at net.fabricmc.loader.launch.knot.KnotClient.main(KnotClient.java:28)
at net.fabricmc.devlaunchinjector.Main.main(Main.java:86)
Caused by: java.lang.Error: Unresolved compilation problems:
ITEM cannot be resolved or is not a field
Identifier cannot be resolved to a type

at xthyo.mega.weapons.MegaWeapons.onInitialize(MegaWeapons.java:16)
at net.fabricmc.loader.entrypoint.minecraft.hooks.EntrypointUtils.invoke0(EntrypointUtils.java:47)
... 12 more

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

-- Head --
Thread: Render thread
Stacktrace:
at net.fabricmc.loader.entrypoint.minecraft.hooks.EntrypointUtils.invoke0(EntrypointUtils.java:50)
at net.fabricmc.loader.entrypoint.minecraft.hooks.EntrypointUtils.invoke(EntrypointUtils.java:33)
at net.fabricmc.loader.entrypoint.minecraft.hooks.EntrypointClient.start(EntrypointClient.java:33)
at net.minecraft.client.MinecraftClient.(MinecraftClient.java:518)

-- Initialization --
Details:
Stacktrace:
at net.minecraft.client.main.Main.main(Main.java:153)
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:78)
at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.base/java.lang.reflect.Method.invoke(Method.java:567)
at net.fabricmc.loader.game.MinecraftGameProvider.launch(MinecraftGameProvider.java:234)
at net.fabricmc.loader.launch.knot.Knot.launch(Knot.java:153)
at net.fabricmc.loader.launch.knot.KnotClient.main(KnotClient.java:28)
at net.fabricmc.devlaunchinjector.Main.main(Main.java:86)

-- System Details --
Details:
Minecraft Version: 1.17.1
Minecraft Version ID: 1.17.1
Operating System: Windows 10 (amd64) version 10.0
Java Version: 16.0.1, AdoptOpenJDK
Java VM Version: OpenJDK 64-Bit Server VM (mixed mode, sharing), AdoptOpenJDK
Memory: 1015770104 bytes (968 MiB) / 1774190592 bytes (1692 MiB) up to 4282384384 bytes (4084 MiB)
CPUs: 16
Processor Vendor: AuthenticAMD
Processor Name: AMD Ryzen 7 2700X Eight-Core Processor
Identifier: AuthenticAMD Family 23 Model 8 Stepping 2
Microarchitecture: unknown
Frequency (GHz): 3.69
Number of physical packages: 1
Number of physical CPUs: 8
Number of logical CPUs: 16
Graphics card #0 name: NVIDIA GeForce RTX 2060
Graphics card #0 vendor: NVIDIA (0x10de)
Graphics card #0 VRAM (MB): 4095.00
Graphics card #0 deviceId: 0x1e89
Graphics card #0 versionInfo: DriverVersion=27.21.14.6677
Memory slot #0 capacity (MB): 8192.00
Memory slot #0 clockSpeed (GHz): 2.13
Memory slot #0 type: DDR4
Memory slot #1 capacity (MB): 8192.00
Memory slot #1 clockSpeed (GHz): 2.13
Memory slot #1 type: DDR4
Virtual memory max (MB): 21964.41
Virtual memory used (MB): 18829.25
Swap memory total (MB): 5632.00
Swap memory used (MB): 160.11
JVM Flags: 4 total; -Xdebug -Xnoagent -Xrunjdwp:transport=dt_socket,address=localhost:60799,server=n,suspend=y -XX:+ShowCodeDetailsInExceptionMessages
Fabric Mods:
fabric: Fabric API 0.37.0+1.17
fabric-api-base: Fabric API Base 0.3.0+a02b446318
fabric-api-lookup-api-v1: Fabric API Lookup API (v1) 1.2.0+2b5c62d018
fabric-biome-api-v1: Fabric Biome API (v1) 3.1.11+c345aea818
fabric-blockrenderlayer-v1: Fabric BlockRenderLayer Registration (v1) 1.1.5+a02b446318
fabric-command-api-v1: Fabric Command API (v1) 1.1.2+6cefd57718
fabric-commands-v0: Fabric Commands (v0) 0.2.2+92519afa18
fabric-containers-v0: Fabric Containers (v0) 0.1.12+a02b446318
fabric-content-registries-v0: Fabric Content Registries (v0) 0.2.2+a02b446318
fabric-crash-report-info-v1: Fabric Crash Report Info (v1) 0.1.5+be9da31018
fabric-dimensions-v1: Fabric Dimensions API (v1) 2.0.11+6cefd57718
fabric-entity-events-v1: Fabric Entity Events (v1) 1.1.0+a02b446318
fabric-events-interaction-v0: Fabric Events Interaction (v0) 0.4.9+a722d8c018
fabric-events-lifecycle-v0: Fabric Events Lifecycle (v0) 0.2.1+92519afa18
fabric-game-rule-api-v1: Fabric Game Rule API (v1) 1.0.7+6cefd57718
fabric-item-api-v1: Fabric Item API (v1) 1.2.4+a02b446318
fabric-item-groups-v0: Fabric Item Groups (v0) 0.2.10+b7ab612118
fabric-key-binding-api-v1: Fabric Key Binding API (v1) 1.0.4+a02b446318
fabric-keybindings-v0: Fabric Key Bindings (v0) 0.2.2+36b77c3e18
fabric-lifecycle-events-v1: Fabric Lifecycle Events (v1) 1.4.4+a02b446318
fabric-loot-tables-v1: Fabric Loot Tables (v1) 1.0.4+a02b446318
fabric-mining-levels-v0: Fabric Mining Levels (v0) 0.1.3+92519afa18
fabric-models-v0: Fabric Models (v0) 0.3.0+a02b446318
fabric-networking-api-v1: Fabric Networking API (v1) 1.0.12+6cefd57718
fabric-networking-blockentity-v0: Fabric Networking Block Entity (v0) 0.2.11+a02b446318
fabric-networking-v0: Fabric Networking (v0) 0.3.2+92519afa18
fabric-object-builder-api-v1: Fabric Object Builder API (v1) 1.10.9+b7ab612118
fabric-object-builders-v0: Fabric Object Builders (v0) 0.7.3+a02b446318
fabric-particles-v1: Fabric Particles (v1) 0.2.4+a02b446318
fabric-registry-sync-v0: Fabric Registry Sync (v0) 0.7.10+e2961fee18
fabric-renderer-api-v1: Fabric Renderer API (v1) 0.4.4+5f02c96918
fabric-renderer-indigo: Fabric Renderer - Indigo 0.4.8+a02b446318
fabric-renderer-registries-v1: Fabric Renderer Registries (v1) 3.2.0+a02b446318
fabric-rendering-data-attachment-v1: Fabric Rendering Data Attachment (v1) 0.1.5+a02b446318
fabric-rendering-fluids-v1: Fabric Rendering Fluids (v1) 0.1.13+a02b446318
fabric-rendering-v0: Fabric Rendering (v0) 1.1.2+92519afa18
fabric-rendering-v1: Fabric Rendering (v1) 1.6.0+a02b446318
fabric-resource-loader-v0: Fabric Resource Loader (v0) 0.4.7+b7ab612118
fabric-screen-api-v1: Fabric Screen API (v1) 1.0.4+155f865c18
fabric-screen-handler-api-v1: Fabric Screen Handler API (v1) 1.1.8+a02b446318
fabric-structure-api-v1: Fabric Structure API (v1) 1.1.12+6cefd57718
fabric-tag-extensions-v0: Fabric Tag Extensions (v0) 1.1.4+a02b446318
fabric-textures-v0: Fabric Textures (v0) 1.0.6+a02b446318
fabric-tool-attribute-api-v1: Fabric Tool Attribute API (v1) 1.2.12+b7ab612118
fabric-transfer-api-v1: Fabric Transfer API (v1) 1.0.0+3fe3c3f518
fabricloader: Fabric Loader 0.11.6
java: OpenJDK 64-Bit Server VM 16
megaweapons: MegaWeapons ${version}
minecraft: Minecraft 1.17.1
Launched Version: Fabric
Backend library: LWJGL version 3.2.2 build 10
Backend API: NO CONTEXT
Window size:
GL Caps: Using framebuffer using OpenGL 3.2
GL debug messages:
Using VBOs: Yes
Is Modded: Definitely; Client brand changed to 'fabric'
Type: Client (map_client.txt)
CPU:

java.lang.Error: Unresolved compilation problems:
ITEM cannot be resolved or is not a field
Identifier cannot be resolved to a type

Learning Java before leaning modding is recommended.