Game crashes with the error below. I've tested with all my other mods, and only Optifine and eguilib get this crash.

---- Minecraft Crash Report ----
// Uh... Did I do that?

Time: 9/28/20 9:38 PM
Description: Rendering overlay

java.lang.NoClassDefFoundError: Could not initialize class javax.imageio.ImageIO
at net.optifine.util.TextureUtils.getImageSize(TextureUtils.java:669) ~[?:?] {re:classloading}
at net.minecraft.client.renderer.texture.AtlasTexture.detectMinimumSpriteSize(AtlasTexture.java:817) ~[?:?] {re:classloading,xf:OptiFine:default}
at net.minecraft.client.renderer.texture.AtlasTexture.detectMaxMipmapLevel(AtlasTexture.java:780) ~[?:?] {re:classloading,xf:OptiFine:default}
at net.minecraft.client.renderer.texture.AtlasTexture.func_229220_a_(AtlasTexture.java:276) ~[?:?] {re:classloading,xf:OptiFine:default}
at net.minecraft.client.renderer.model.ModelBakery.processLoading(ModelBakery.java:257) ~[?:?] {re:classloading,pl:accesstransformer:B,xf:OptiFine:default}
at net.minecraftforge.client.model.ModelLoader.(ModelLoader.java:72) ~[?:?] {re:classloading}
at net.minecraft.client.renderer.model.ModelManager.func_212854_a_(ModelManager.java:57) ~[?:?] {re:classloading,pl:runtimedistcleaner:A}
at net.minecraft.client.renderer.model.ModelManager.func_212854_a_(ModelManager.java:20) ~[?:?] {re:classloading,pl:runtimedistcleaner:A}
at net.minecraft.client.resources.ReloadListener.func_215270_b(SourceFile:11) ~[?:?] {re:classloading}
at net.minecraft.client.resources.ReloadListener$$Lambda$3338/721286839.get(Unknown Source) ~[?:?] {}
at java.util.concurrent.CompletableFuture$AsyncSupply.run(CompletableFuture.java:1582) ~[?:1.8.0_51] {}
at java.util.concurrent.CompletableFuture$AsyncSupply.exec(CompletableFuture.java:1574) ~[?:1.8.0_51] {}
at java.util.concurrent.ForkJoinTask.doExec(ForkJoinTask.java:289) ~[?:1.8.0_51] {}
at java.util.concurrent.ForkJoinPool$WorkQueue.runTask(ForkJoinPool.java:1056) ~[?:1.8.0_51] {}
at java.util.concurrent.ForkJoinPool.runWorker(ForkJoinPool.java:1689) ~[?:1.8.0_51] {re:computing_frames}
at java.util.concurrent.ForkJoinWorkerThread.run(ForkJoinWorkerThread.java:157) ~[?:1.8.0_51] {}

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

-- Head --
Thread: Render thread
Stacktrace:
at net.optifine.util.TextureUtils.getImageSize(TextureUtils.java:669) ~[?:?] {re:classloading}
-- Overlay render details --
Details:
Overlay name: net.minecraft.client.gui.ResourceLoadProgressGui
Stacktrace:
at net.minecraft.client.renderer.GameRenderer.func_195458_a(GameRenderer.java:807) ~[?:?] {re:classloading,pl:accesstransformer:B,xf:OptiFine:default}
at net.minecraft.client.Minecraft.func_195542_b(Minecraft.java:953) [?:?] {re:classloading,pl:accesstransformer:B,pl:runtimedistcleaner:A,re:mixin,pl:accesstransformer:B,pl:runtimedistcleaner:A}
at net.minecraft.client.Minecraft.func_99999_d(Minecraft.java:584) [?:?] {re:classloading,pl:accesstransformer:B,pl:runtimedistcleaner:A,re:mixin,pl:accesstransformer:B,pl:runtimedistcleaner:A}
at net.minecraft.client.main.Main.main(Main.java:184) [?:?] {re:classloading,pl:runtimedistcleaner:A}
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[?:1.8.0_51] {}
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[?:1.8.0_51] {}
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[?:1.8.0_51] {}
at java.lang.reflect.Method.invoke(Method.java:497) ~[?:1.8.0_51] {}
at net.minecraftforge.fml.loading.FMLClientLaunchProvider.lambda$launchService$0(FMLClientLaunchProvider.java:51) [forge-1.16.3-34.1.0.jar:34.1] {}
at net.minecraftforge.fml.loading.FMLClientLaunchProvider$$Lambda$443/1420623741.call(Unknown Source) [forge-1.16.3-34.1.0.jar:34.1] {}
at cpw.mods.modlauncher.LaunchServiceHandlerDecorator.launch(LaunchServiceHandlerDecorator.java:37) [modlauncher-7.0.1.jar:?] {}
at cpw.mods.modlauncher.LaunchServiceHandler.launch(LaunchServiceHandler.java:54) [modlauncher-7.0.1.jar:?] {}
at cpw.mods.modlauncher.LaunchServiceHandler.launch(LaunchServiceHandler.java:72) [modlauncher-7.0.1.jar:?] {}
at cpw.mods.modlauncher.Launcher.run(Launcher.java:81) [modlauncher-7.0.1.jar:?] {}
at cpw.mods.modlauncher.Launcher.main(Launcher.java:65) [modlauncher-7.0.1.jar:?] {}

-- System Details --
Details:
Minecraft Version: 1.16.3
Minecraft Version ID: 1.16.3
Operating System: Windows 10 (amd64) version 10.0
Java Version: 1.8.0_51, Oracle Corporation
Java VM Version: Java HotSpot(TM) 64-Bit Server VM (mixed mode), Oracle Corporation
Memory: 6780655072 bytes (6466 MB) / 7247757312 bytes (6912 MB) up to 10737418240 bytes (10240 MB)
CPUs: 4
JVM Flags: 9 total; -XX:HeapDumpPath=MojangTricksIntelDriversForPerformance_javaw.exe_minecraft.exe.heapdump -Xss1M -Xmx10G -XX:+UnlockExperimentalVMOptions -XX:+UseG1GC -XX:G1NewSizePercent=20 -XX:G1ReservePercent=20 -XX:MaxGCPauseMillis=50 -XX:G1HeapRegionSize=32M
ModLauncher: 7.0.1+78+master.e9771d8
ModLauncher launch target: fmlclient
ModLauncher naming: srg
ModLauncher services:
/mixin-0.8.1.jar mixin PLUGINSERVICE
/eventbus-3.0.3-service.jar eventbus PLUGINSERVICE
/forge-1.16.3-34.1.0.jar object_holder_definalize PLUGINSERVICE
/forge-1.16.3-34.1.0.jar runtime_enum_extender PLUGINSERVICE
/accesstransformers-2.2.0-shadowed.jar accesstransformer PLUGINSERVICE
/forge-1.16.3-34.1.0.jar capability_inject_definalize PLUGINSERVICE
/forge-1.16.3-34.1.0.jar runtimedistcleaner PLUGINSERVICE
/mixin-0.8.1.jar mixin TRANSFORMATIONSERVICE
/OptiFine_1.16.3_HD_U_G3.jar OptiFine TRANSFORMATIONSERVICE
/forge-1.16.3-34.1.0.jar fml TRANSFORMATIONSERVICE
FML: 34.1
Forge: net.minecraftforge:34.1.0
FML Language Providers:
[email protected]
minecraft@1
Mod List:
forge-1.16.3-34.1.0-client.jar Minecraft {[email protected] NONE}
randomblockplacement-1.16.2-forge33.0.5-1.0.jar RandomBlockPlacement {[email protected] NONE}
eguilib-1.0.3-1.16.jar Erdbeerbaer's GUI Library {[email protected] NONE}
forge-1.16.3-34.1.0-universal.jar Forge {[email protected] NONE}
worldedit-forge-mc1.16.3-7.2.0-beta-05.jar WorldEdit {[email protected]+20b3da4 NONE}
MinersAdvantage-1.16.3-1.7.3.153-1.16.jar MinersAdvantage {[email protected] NONE}
Launched Version: 1.16.3-forge-34.1.0
Backend library: LWJGL version 3.2.2 build 10
Backend API: GeForce GTX 970/PCIe/SSE2 GL version 4.6.0 NVIDIA 452.06, NVIDIA Corporation
GL Caps: Using framebuffer using OpenGL 3.0
Using VBOs: Yes
Is Modded: Definitely; Client brand changed to 'forge'
Type: Client (map_client.txt)
Graphics mode: fabulous
Resource Packs:
Current Language: English (US)
CPU: 4x Intel(R) Core(TM) i5-6500 CPU @ 3.20GHz
OptiFine Version: OptiFine_1.16.3_HD_U_G3
OptiFine Build: 20200916-082411
Render Distance Chunks: 20
Mipmaps: 4
Anisotropic Filtering: 1
Antialiasing: 0
Multitexture: false
Shaders: null
OpenGlVersion: 4.6.0 NVIDIA 452.06
OpenGlRenderer: GeForce GTX 970/PCIe/SSE2
OpenGlVendor: NVIDIA Corporation
CpuCount: 4

(Forgot to close)
Should be fixed now