when you place a new hyperbox and enter it, it crashes the game. everything is fine afterwards and its still useable just annoying. i have DREAMT of a mod like this and will do literally anything to help fix this crash

I'm unable to reproduce any crashes, can you pastebin the crash log?

Encountered an unexpected exception net.minecraft.crash.ReportedException: Exception ticking world at net.minecraft.server.MinecraftServer.func_71190_q(MinecraftServer.java:855) at net.minecraft.server.MinecraftServer.func_71217_p(MinecraftServer.java:787) at net.minecraft.server.integrated.IntegratedServer.func_71217_p(IntegratedServer.java:118) at net.minecraft.server.MinecraftServer.func_240802_v_(MinecraftServer.java:642) at net.minecraft.server.MinecraftServer.func_240783_a_(MinecraftServer.java:232) at net.minecraft.server.MinecraftServer$$Lambda$17675/551044335.run(Unknown Source) at java.lang.Thread.run(Thread.java:745) Caused by: java.lang.RuntimeException: Missing Dimension ResourceKey[minecraft:dimension / hyperbox:generated_hyperbox/502236bb-2949-490c-9fa4-5e88df7b3357] at com.qouteall.immersive_portals.dimension_sync.DimensionIdRecord.getIntId(DimensionIdRecord.java:39) at com.qouteall.immersive_portals.dimension_sync.DimId.writeWorldId(DimId.java:24) at com.qouteall.hiding_in_the_bushes.network.StcRedirected.encode(StcRedirected.java:59) at com.qouteall.hiding_in_the_bushes.network.NetworkMain$$Lambda$14418/1601365206.accept(Unknown Source) at net.minecraftforge.fml.network.simple.IndexedMessageCodec.lambda$tryEncode$4(IndexedMessageCodec.java:134) at net.minecraftforge.fml.network.simple.IndexedMessageCodec$$Lambda$19354/829426955.accept(Unknown Source) at java.util.Optional.ifPresent(Optional.java:159) at net.minecraftforge.fml.network.simple.IndexedMessageCodec.tryEncode(IndexedMessageCodec.java:132) at net.minecraftforge.fml.network.simple.IndexedMessageCodec.build(IndexedMessageCodec.java:147) at net.minecraftforge.fml.network.simple.SimpleChannel.encodeMessage(SimpleChannel.java:85) at net.minecraftforge.fml.network.simple.SimpleChannel.toBuffer(SimpleChannel.java:98) at net.minecraftforge.fml.network.simple.SimpleChannel.toVanillaPacket(SimpleChannel.java:129) at com.qouteall.hiding_in_the_bushes.MyNetwork.createRedirectedMessage(MyNetwork.java:47) at net.minecraft.server.management.PlayerList.handler$bgi000$sendToDimension(PlayerList.java:2464) at net.minecraft.server.management.PlayerList.func_232642_a_(PlayerList.java) at net.minecraft.world.server.ServerWorld.func_72835_b(ServerWorld.java:293) at net.minecraft.server.MinecraftServer.func_71190_q(MinecraftServer.java:851) ... 6 more

Might be a problem with Immersive Portals, it looks like they're not currently able to handle dimensions being unloaded.

They may or may not be able to prevent this crash on their end, otherwise it might not be fixable until forge gets a standard API for handling dynamic dimensions again