java.lang.IllegalStateException: Start called twice in a row
at Not Enough Crashes deobfuscated stack trace.(1.17.1+build.61)
at com.github.burgerguy.hudtweaks.util.gl.DrawTest.markStart(DrawTest.java:25)
at com.github.burgerguy.hudtweaks.hud.element.HudElementContainer.markDrawTestStart(HudElementContainer.java:123)
at com.github.burgerguy.hudtweaks.util.RenderStateUtil.startRender(RenderStateUtil.java:22)
at com.github.burgerguy.hudtweaks.util.RenderStateUtil.startRender(RenderStateUtil.java:16)
at net.minecraft.client.gui.hud.BossBarHud.handler$bji000$renderBossBarHead(BossBarHud:1517)
at net.minecraft.client.gui.hud.BossBarHud.render(BossBarHud)
at net.minecraft.client.gui.hud.InGameHud.redirect$cia000$onRenderBossBarsInRender(InGameHud:10082)
at net.minecraft.client.gui.hud.InGameHud.render(InGameHud:254)
at net.minecraft.client.render.GameRenderer.render(GameRenderer:1217)
at net.minecraft.client.MinecraftClient.render(MinecraftClient:1117)
at net.minecraft.client.MinecraftClient.run(MinecraftClient:733)
at fudge.notenoughcrashes.mixinhandlers.InGameCatcher.handleClientCrash(InGameCatcher.java:37)
at net.minecraft.client.MinecraftClient.modify$cdm000$atTheEndOfSecondCatchBeforePrintingCrashReport(MinecraftClient:23046)
at net.minecraft.client.MinecraftClient.run(MinecraftClient:760)
at fudge.notenoughcrashes.mixinhandlers.InGameCatcher.handleClientCrash(InGameCatcher.java:37)
at net.minecraft.client.MinecraftClient.modify$cdm000$atTheEndOfSecondCatchBeforePrintingCrashReport(MinecraftClient:23046)
at net.minecraft.client.MinecraftClient.run(MinecraftClient:760)
at fudge.notenoughcrashes.mixinhandlers.InGameCatcher.handleClientCrash(InGameCatcher.java:37)
at net.minecraft.client.MinecraftClient.modify$cdm000$atTheEndOfFirstCatchBeforePrintingCrashReport(MinecraftClient:23035)
at net.minecraft.client.MinecraftClient.run(MinecraftClient:755)
at net.minecraft.client.main.Main.main(Main:238)
at jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:77)
at jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:568)
at net.fabricmc.loader.impl.game.minecraft.MinecraftGameProvider.launch(MinecraftGameProvider.java:608)
at net.fabricmc.loader.impl.launch.knot.Knot.launch(Knot.java:77)
at net.fabricmc.loader.impl.launch.knot.KnotClient.main(KnotClient.java:23)

-- Head --
Thread: Render thread
Stacktrace:
at com.github.burgerguy.hudtweaks.util.gl.DrawTest.markStart(DrawTest.java:25)
at com.github.burgerguy.hudtweaks.hud.element.HudElementContainer.markDrawTestStart(HudElementContainer.java:123)
at com.github.burgerguy.hudtweaks.util.RenderStateUtil.startRender(RenderStateUtil.java:22)
at com.github.burgerguy.hudtweaks.util.RenderStateUtil.startRender(RenderStateUtil.java:16)
at net.minecraft.class_337.handler$bji000$renderBossBarHead(class_337.java:1517)
at net.minecraft.class_337.method_1796(class_337.java)
at net.minecraft.class_329.redirect$cia000$onRenderBossBarsInRender(class_329.java:10082)
at net.minecraft.class_329.method_1753(class_329.java:254)

oh yeaaaaaah, fixed TYSM ♥

this should be fixed in the latest version, can you confirm?
also, spiffyhud is now marked to break this mod, so you can't have both at once. there's pretty much no way to get around this for the time being.

Can you post your mods list and your mc version? It isn't crashing for me but other people seem to have problems with it.

1.18.1 - Fabric
Every single mod in it is Client-Sided only

Could you package and send a link to all of the mods for testing? I can't reasonably fix it without all of them.

okay then, imma upload it in mediafire cause for some reason i cant send it directly here
https://www.mediafire.com/file/vwjzhyhfj6uz7ow/mods.zip/file