1.20 [Solved] Custom 1.20 Mod Pack Error Code 1 due to duplicate mods

[NanoWano90]

I cant load my mod pack and it will crash and give me error code 1, all I would like to know is what is giving me this issue

 

Latest Log

Spoiler

[22Jul2023 11:39:36.110] [main/INFO] [cpw.mods.modlauncher.Launcher/MODLAUNCHER]: ModLauncher running: args [--username, NanoWano90, --version, forge-46.0.14, --gameDir, C:\Users\kaids\curseforge\minecraft\Instances\Client Side Mods, --assetsDir, C:\Users\kaids\curseforge\minecraft\Install\assets, --assetIndex, 5, --uuid, c7186288ccae4735b5debb4eb5badb08, --accessToken, ????????, --clientId, YzA4OWQxODktMmEyNS00ZjM5LWJhNWUtMzk5MTU2NDA1OTdj, --xuid, 2535431459704944, --userType, msa, --versionType, release, --width, 1920, --height, 1080, --launchTarget, forgeclient, --fml.forgeVersion, 46.0.14, --fml.mcVersion, 1.20, --fml.forgeGroup, net.minecraftforge, --fml.mcpVersion, 20230608.053357]
[22Jul2023 11:39:36.115] [main/INFO] [cpw.mods.modlauncher.Launcher/MODLAUNCHER]: ModLauncher 10.0.8+10.0.8+main.0ef7e830 starting: java version 17.0.3 by Microsoft; OS Windows 11 arch amd64 version 10.0
[22Jul2023 11:39:37.198] [main/INFO] [gg.essential.loader.stage1.EssentialLoaderBase/]: Starting Essential Loader (stage2) version 1.4.1 (4b3b87be87d34916028dffa85460d085) [stable]
[22Jul2023 11:39:37.204] [main/INFO] [optifine.OptiFineTransformationService/]: OptiFineTransformationService.onLoad
[22Jul2023 11:39:37.205] [main/INFO] [optifine.OptiFineTransformationService/]: OptiFine ZIP file URL: union:/C:/Users/kaids/curseforge/minecraft/Instances/Client%20Side%20Mods/mods/preview_OptiFine_1.20_HD_U_I5_pre5.jar%23203!/
[22Jul2023 11:39:37.210] [main/INFO] [optifine.OptiFineTransformationService/]: OptiFine ZIP file: C:\Users\kaids\curseforge\minecraft\Instances\Client Side Mods\mods\preview_OptiFine_1.20_HD_U_I5_pre5.jar
[22Jul2023 11:39:37.211] [main/INFO] [optifine.OptiFineTransformer/]: Target.PRE_CLASS is available
[22Jul2023 11:39:37.247] [main/INFO] [mixin/]: SpongePowered MIXIN Subsystem Version=0.8.5 Source=union:/C:/Users/kaids/curseforge/minecraft/Install/libraries/org/spongepowered/mixin/0.8.5/mixin-0.8.5.jar%2399!/ Service=ModLauncher Env=CLIENT
[22Jul2023 11:39:37.257] [main/INFO] [optifine.OptiFineTransformationService/]: OptiFineTransformationService.initialize
[22Jul2023 11:39:37.451] [main/ERROR] [gg.essential.loader.stage2.EssentialLoaderBase/]: Error occurred fetching https://api.essential.gg/mods/v1/essential:essential/versions/stable/platforms/forge_1-20:
java.io.FileNotFoundException: https://api.essential.gg/mods/v1/essential:essential/versions/stable/platforms/forge_1-20
    at sun.net.www.protocol.http.HttpURLConnection.getInputStream0(HttpURLConnection.java:1993) ~[?:?]
    at sun.net.www.protocol.http.HttpURLConnection.getInputStream(HttpURLConnection.java:1589) ~[?:?]
    at sun.net.www.protocol.https.HttpsURLConnectionImpl.getInputStream(HttpsURLConnectionImpl.java:224) ~[?:?]
    at gg.essential.loader.stage2.EssentialLoaderBase.fetchJsonObject(EssentialLoaderBase.java:553) ~[?:?]
    at gg.essential.loader.stage2.EssentialLoaderBase.fetchLatestVersion(EssentialLoaderBase.java:574) ~[?:?]
    at gg.essential.loader.stage2.EssentialLoaderBase.loadMod(EssentialLoaderBase.java:252) ~[?:?]
    at gg.essential.loader.stage2.EssentialLoaderBase.load(EssentialLoaderBase.java:132) ~[?:?]
    at gg.essential.loader.stage2.EssentialTransformationService.beginScanning(EssentialTransformationService.java:180) ~[?:?]
    at gg.essential.loader.stage1.util.IDelegatingTransformationService.beginScanning(IDelegatingTransformationService.java:12) ~[?:?]
    at gg.essential.container.loader.stage0.util.IDelegatingTransformationService.beginScanning(IDelegatingTransformationService.java:12) ~[?:?]
    at cpw.mods.modlauncher.TransformationServiceDecorator.runScan(TransformationServiceDecorator.java:112) ~[modlauncher-10.0.8.jar:?]
    at cpw.mods.modlauncher.TransformationServicesHandler.lambda$runScanningTransformationServices$8(TransformationServicesHandler.java:100) ~[modlauncher-10.0.8.jar:?]
    at java.util.stream.ReferencePipeline$3$1.accept(ReferencePipeline.java:197) ~[?:?]
    at java.util.HashMap$ValueSpliterator.forEachRemaining(HashMap.java:1779) ~[?:?]
    at java.util.stream.AbstractPipeline.copyInto(AbstractPipeline.java:509) ~[?:?]
    at java.util.stream.AbstractPipeline.wrapAndCopyInto(AbstractPipeline.java:499) ~[?:?]
    at java.util.stream.AbstractPipeline.evaluate(AbstractPipeline.java:575) ~[?:?]
    at java.util.stream.AbstractPipeline.evaluateToArrayNode(AbstractPipeline.java:260) ~[?:?]
    at java.util.stream.ReferencePipeline.toArray(ReferencePipeline.java:616) ~[?:?]
    at java.util.stream.ReferencePipeline.toArray(ReferencePipeline.java:622) ~[?:?]
    at java.util.stream.ReferencePipeline.toList(ReferencePipeline.java:627) ~[?:?]
    at cpw.mods.modlauncher.TransformationServicesHandler.runScanningTransformationServices(TransformationServicesHandler.java:102) ~[modlauncher-10.0.8.jar:?]
    at cpw.mods.modlauncher.TransformationServicesHandler.initializeTransformationServices(TransformationServicesHandler.java:55) ~[modlauncher-10.0.8.jar:?]
    at cpw.mods.modlauncher.Launcher.run(Launcher.java:87) ~[modlauncher-10.0.8.jar:?]
    at cpw.mods.modlauncher.Launcher.main(Launcher.java:77) ~[modlauncher-10.0.8.jar:?]
    at cpw.mods.modlauncher.BootstrapLaunchConsumer.accept(BootstrapLaunchConsumer.java:26) ~[modlauncher-10.0.8.jar:?]
    at cpw.mods.modlauncher.BootstrapLaunchConsumer.accept(BootstrapLaunchConsumer.java:23) ~[modlauncher-10.0.8.jar:?]
    at cpw.mods.bootstraplauncher.BootstrapLauncher.main(BootstrapLauncher.java:141) ~[bootstraplauncher-1.1.2.jar:?]
[22Jul2023 11:39:37.457] [main/ERROR] [gg.essential.loader.stage2.EssentialLoaderBase/]: url: https://api.essential.gg/mods/v1/essential:essential/versions/stable/platforms/forge_1-20
[22Jul2023 11:39:37.458] [main/ERROR] [gg.essential.loader.stage2.EssentialLoaderBase/]: cf-ray: 7ead1eebcf8910bf-ORD
[22Jul2023 11:39:37.458] [main/WARN] [gg.essential.loader.stage2.EssentialLoaderBase/]: Essential does not support the following game version: forge_1.20
[22Jul2023 11:39:37.698] [main/WARN] [net.minecraftforge.fml.loading.moddiscovery.ModFileParser/LOADING]: Mod file C:\Users\kaids\curseforge\minecraft\Install\libraries\net\minecraftforge\fmlcore\1.20-46.0.14\fmlcore-1.20-46.0.14.jar is missing mods.toml file
[22Jul2023 11:39:37.700] [main/WARN] [net.minecraftforge.fml.loading.moddiscovery.ModFileParser/LOADING]: Mod file C:\Users\kaids\curseforge\minecraft\Install\libraries\net\minecraftforge\javafmllanguage\1.20-46.0.14\javafmllanguage-1.20-46.0.14.jar is missing mods.toml file
[22Jul2023 11:39:37.702] [main/WARN] [net.minecraftforge.fml.loading.moddiscovery.ModFileParser/LOADING]: Mod file C:\Users\kaids\curseforge\minecraft\Install\libraries\net\minecraftforge\lowcodelanguage\1.20-46.0.14\lowcodelanguage-1.20-46.0.14.jar is missing mods.toml file
[22Jul2023 11:39:37.704] [main/WARN] [net.minecraftforge.fml.loading.moddiscovery.ModFileParser/LOADING]: Mod file C:\Users\kaids\curseforge\minecraft\Install\libraries\net\minecraftforge\mclanguage\1.20-46.0.14\mclanguage-1.20-46.0.14.jar is missing mods.toml file
[22Jul2023 11:39:37.720] [main/ERROR] [net.minecraftforge.fml.loading.moddiscovery.ModDiscoverer/SCAN]: Failed to build unique mod list after mod discovery.
net.minecraftforge.fml.loading.EarlyLoadingException: Duplicate mods found
    at net.minecraftforge.fml.loading.UniqueModListBuilder.buildUniqueList(UniqueModListBuilder.java:78) ~[fmlloader-1.20-46.0.14.jar:1.0]
    at net.minecraftforge.fml.loading.moddiscovery.ModDiscoverer.discoverMods(ModDiscoverer.java:105) ~[fmlloader-1.20-46.0.14.jar:?]
    at net.minecraftforge.fml.loading.FMLLoader.beginModScan(FMLLoader.java:166) ~[fmlloader-1.20-46.0.14.jar:1.0]
    at net.minecraftforge.fml.loading.FMLServiceProvider.beginScanning(FMLServiceProvider.java:86) ~[fmlloader-1.20-46.0.14.jar:1.0]
    at cpw.mods.modlauncher.TransformationServiceDecorator.runScan(TransformationServiceDecorator.java:112) ~[modlauncher-10.0.8.jar:?]
    at cpw.mods.modlauncher.TransformationServicesHandler.lambda$runScanningTransformationServices$8(TransformationServicesHandler.java:100) ~[modlauncher-10.0.8.jar:?]
    at java.util.stream.ReferencePipeline$3$1.accept(ReferencePipeline.java:197) ~[?:?]
    at java.util.HashMap$ValueSpliterator.forEachRemaining(HashMap.java:1779) ~[?:?]
    at java.util.stream.AbstractPipeline.copyInto(AbstractPipeline.java:509) ~[?:?]
    at java.util.stream.AbstractPipeline.wrapAndCopyInto(AbstractPipeline.java:499) ~[?:?]
    at java.util.stream.AbstractPipeline.evaluate(AbstractPipeline.java:575) ~[?:?]
    at java.util.stream.AbstractPipeline.evaluateToArrayNode(AbstractPipeline.java:260) ~[?:?]
    at java.util.stream.ReferencePipeline.toArray(ReferencePipeline.java:616) ~[?:?]
    at java.util.stream.ReferencePipeline.toArray(ReferencePipeline.java:622) ~[?:?]
    at java.util.stream.ReferencePipeline.toList(ReferencePipeline.java:627) ~[?:?]
    at cpw.mods.modlauncher.TransformationServicesHandler.runScanningTransformationServices(TransformationServicesHandler.java:102) ~[modlauncher-10.0.8.jar:?]
    at cpw.mods.modlauncher.TransformationServicesHandler.initializeTransformationServices(TransformationServicesHandler.java:55) ~[modlauncher-10.0.8.jar:?]
    at cpw.mods.modlauncher.Launcher.run(Launcher.java:87) ~[modlauncher-10.0.8.jar:?]
    at cpw.mods.modlauncher.Launcher.main(Launcher.java:77) ~[modlauncher-10.0.8.jar:?]
    at cpw.mods.modlauncher.BootstrapLaunchConsumer.accept(BootstrapLaunchConsumer.java:26) ~[modlauncher-10.0.8.jar:?]
    at cpw.mods.modlauncher.BootstrapLaunchConsumer.accept(BootstrapLaunchConsumer.java:23) ~[modlauncher-10.0.8.jar:?]
    at cpw.mods.bootstraplauncher.BootstrapLauncher.main(BootstrapLauncher.java:141) ~[bootstraplauncher-1.1.2.jar:?]
[22Jul2023 11:39:37.722] [main/ERROR] [net.minecraftforge.fml.loading.moddiscovery.ModDiscoverer/SCAN]: Mod Discovery failed. Skipping dependency discovery.

 

Edited July 23, 2023 by Paint_Ninja
Edit title for searchability

[LexManos]

Quote

 Failed to build unique mod list after mod discovery.
net.minecraftforge.fml.loading.EarlyLoadingException: Duplicate mods found

You have the same mod installed more then once, no idea what one it is, we used to have them listed in the log, so try checking the debug log. 

[Paint_Ninja]

It's not listed in the log because he's using 1.20 instead of 1.20.1.

[LexManos]

Ya, but the debug log should still contain the loaded mods, the enhanced exception was added later I guess.

[NanoWano90]

 I figured out what mod was duplicated, thank you.