Before Continuing:

• Always check you are using the latest version of the mods and its dependencies
• Remove known problematic rendering mods such as Optifine, Sodium and others. Do NOT report issues related to said mods
• If you are unsure which mod is the culprit.
  Disable half your mods at time until you isolate the culprit
• If you have a crash ALWAYS post LATEST.LOG below
• If the issue is about behaviors be sure to consult the WIKI first

Version-Loader

1.20.1-fabric

Supplementaries Version

supplementaries 1.20-2.7.14

Moonlight Lib Version

moonlight 1.20-2.8.70

Issue Detail

Joining server failed if failed to download the following https://raw.githubusercontent.com/MehVahdJukaar/Supplementaries/master/credits.json

I know this is not the newest version, but it is provided by Modpack prominence 2.

Optional Attachment

[18:39:05] [Netty Client IO #6/ERROR]: Registry remapping failed!
java.util.concurrent.TimeoutException: null
at java.util.concurrent.CompletableFuture.timedGet(CompletableFuture.java:1960) ~[?:?]
at java.util.concurrent.CompletableFuture.get(CompletableFuture.java:2095) ~[?:?]
at net.fabricmc.fabric.impl.registry.sync.RegistrySyncManager.receivePacket(RegistrySyncManager.java:124) ~[fabric-registry-sync-v0-2.3.2+4df89eb277-3830ec6d52dbef83.jar:?]
at net.fabricmc.fabric.impl.client.registry.sync.FabricRegistryClientInit.lambda$registerSyncPacketReceiver$2(FabricRegistryClientInit.java:40) ~[fabric-registry-sync-v0-2.3.2+4df89eb277-3830ec6d52dbef83.jar:?]
at net.fabricmc.fabric.impl.networking.client.ClientPlayNetworkAddon.receive(ClientPlayNetworkAddon.java:98) ~[fabric-networking-api-v1-1.3.10+eeb8eb3677-5f0732b3ac824797.jar:?]
at net.fabricmc.fabric.impl.networking.client.ClientPlayNetworkAddon.receive(ClientPlayNetworkAddon.java:40) ~[fabric-networking-api-v1-1.3.10+eeb8eb3677-5f0732b3ac824797.jar:?]
at net.fabricmc.fabric.impl.networking.AbstractChanneledNetworkAddon.handle(AbstractChanneledNetworkAddon.java:101) ~[fabric-networking-api-v1-1.3.10+eeb8eb3677-5f0732b3ac824797.jar:?]
at net.fabricmc.fabric.impl.networking.client.ClientPlayNetworkAddon.handle(ClientPlayNetworkAddon.java:90) ~[fabric-networking-api-v1-1.3.10+eeb8eb3677-5f0732b3ac824797.jar:?]
at net.minecraft.client.network.ClientPlayNetworkHandler.handler$fdh000$fabric-networking-api-v1$handleCustomPayload(ClientPlayNetworkHandler.java:4268) ~[client-intermediary.jar:?]
at net.minecraft.client.network.ClientPlayNetworkHandler.onCustomPayload(ClientPlayNetworkHandler.java) ~[client-intermediary.jar:?]
at net.minecraft.network.packet.s2c.play.CustomPayloadS2CPacket.apply(CustomPayloadS2CPacket.java:60) ~[client-intermediary.jar:?]
at net.minecraft.network.packet.s2c.play.CustomPayloadS2CPacket.apply(CustomPayloadS2CPacket.java:8) ~[client-intermediary.jar:?]
at net.minecraft.network.ClientConnection.handlePacket(ClientConnection.java:175) ~[client-intermediary.jar:?]
at net.minecraft.network.ClientConnection.channelRead0(ClientConnection.java:160) ~[client-intermediary.jar:?]
at net.minecraft.network.ClientConnection.channelRead0(ClientConnection.java:52) ~[client-intermediary.jar:?]
at io.netty.channel.SimpleChannelInboundHandler.channelRead(SimpleChannelInboundHandler.java:99) ~[netty-transport-4.1.82.Final.jar:?]
at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:379) ~[netty-transport-4.1.82.Final.jar:?]
at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:365) ~[netty-transport-4.1.82.Final.jar:?]
at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:357) ~[netty-transport-4.1.82.Final.jar:?]
at io.netty.handler.codec.MessageToMessageDecoder.channelRead(MessageToMessageDecoder.java:103) ~[netty-codec-4.1.82.Final.jar:?]
at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:379) ~[netty-transport-4.1.82.Final.jar:?]
at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:365) ~[netty-transport-4.1.82.Final.jar:?]
at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:357) ~[netty-transport-4.1.82.Final.jar:?]
at io.netty.handler.codec.ByteToMessageDecoder.fireChannelRead(ByteToMessageDecoder.java:336) ~[netty-codec-4.1.82.Final.jar:?]
at io.netty.handler.codec.ByteToMessageDecoder.channelRead(ByteToMessageDecoder.java:308) ~[netty-codec-4.1.82.Final.jar:?]
at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:379) ~[netty-transport-4.1.82.Final.jar:?]
at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:365) ~[netty-transport-4.1.82.Final.jar:?]
at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:357) ~[netty-transport-4.1.82.Final.jar:?]
at io.netty.handler.codec.ByteToMessageDecoder.fireChannelRead(ByteToMessageDecoder.java:336) ~[netty-codec-4.1.82.Final.jar:?]
at io.netty.handler.codec.ByteToMessageDecoder.channelRead(ByteToMessageDecoder.java:308) ~[netty-codec-4.1.82.Final.jar:?]
at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:379) ~[netty-transport-4.1.82.Final.jar:?]
at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:365) ~[netty-transport-4.1.82.Final.jar:?]
at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:357) ~[netty-transport-4.1.82.Final.jar:?]
at io.netty.handler.codec.ByteToMessageDecoder.fireChannelRead(ByteToMessageDecoder.java:336) ~[netty-codec-4.1.82.Final.jar:?]
at io.netty.handler.codec.ByteToMessageDecoder.fireChannelRead(ByteToMessageDecoder.java:323) ~[netty-codec-4.1.82.Final.jar:?]
at io.netty.handler.codec.ByteToMessageDecoder.callDecode(ByteToMessageDecoder.java:444) ~[netty-codec-4.1.82.Final.jar:?]
at io.netty.handler.codec.ByteToMessageDecoder.channelRead(ByteToMessageDecoder.java:280) ~[netty-codec-4.1.82.Final.jar:?]
at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:379) ~[netty-transport-4.1.82.Final.jar:?]
at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:365) ~[netty-transport-4.1.82.Final.jar:?]
at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:357) ~[netty-transport-4.1.82.Final.jar:?]
at io.netty.handler.codec.MessageToMessageDecoder.channelRead(MessageToMessageDecoder.java:103) ~[netty-codec-4.1.82.Final.jar:?]
at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:379) ~[netty-transport-4.1.82.Final.jar:?]
at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:365) ~[netty-transport-4.1.82.Final.jar:?]
at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:357) ~[netty-transport-4.1.82.Final.jar:?]
at io.netty.handler.timeout.IdleStateHandler.channelRead(IdleStateHandler.java:286) ~[netty-handler-4.1.82.Final.jar:?]
at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:379) ~[netty-transport-4.1.82.Final.jar:?]
at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:365) ~[netty-transport-4.1.82.Final.jar:?]
at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:357) ~[netty-transport-4.1.82.Final.jar:?]
at io.netty.channel.DefaultChannelPipeline$HeadContext.channelRead(DefaultChannelPipeline.java:1410) ~[netty-transport-4.1.82.Final.jar:?]
at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:379) ~[netty-transport-4.1.82.Final.jar:?]
at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:365) ~[netty-transport-4.1.82.Final.jar:?]
at io.netty.channel.DefaultChannelPipeline.fireChannelRead(DefaultChannelPipeline.java:919) ~[netty-transport-4.1.82.Final.jar:?]
at io.netty.channel.nio.AbstractNioByteChannel$NioByteUnsafe.read(AbstractNioByteChannel.java:166) ~[netty-transport-4.1.82.Final.jar:?]
at io.netty.channel.nio.NioEventLoop.processSelectedKey(NioEventLoop.java:788) ~[netty-transport-4.1.82.Final.jar:?]
at io.netty.channel.nio.NioEventLoop.processSelectedKeysOptimized(NioEventLoop.java:724) ~[netty-transport-4.1.82.Final.jar:?]
at io.netty.channel.nio.NioEventLoop.processSelectedKeys(NioEventLoop.java:650) ~[netty-transport-4.1.82.Final.jar:?]
at io.netty.channel.nio.NioEventLoop.run(NioEventLoop.java:562) ~[netty-transport-4.1.82.Final.jar:?]
at io.netty.util.concurrent.SingleThreadEventExecutor$4.run(SingleThreadEventExecutor.java:997) ~[netty-common-4.1.82.Final.jar:?]
at io.netty.util.internal.ThreadExecutorMap$2.run(ThreadExecutorMap.java:74) ~[netty-common-4.1.82.Final.jar:?]
at java.lang.Thread.run(Thread.java:833) ~[?:?]

To Produce

Maybe just block raw.githubusercontent.com and https://gist.githubusercontent.com
You can re-produce it.

You sure that's what's happening? I don't see it mentioned there