when player got some effect then game crashes because it cannot show GUI icon that includes golden apples, enemies etc. I hope this will be fixed very soon
(it includes forges on 1.20 and 1.20.1) ❤️
maybe this'll help :
The game crashed whilst unexpected error Error: java.lang.NoSuchMethodError: 'boolean net.minecraftforge.client.extensions.common.IClientMobEffectExtensions.renderGuiIcon(net.minecraft.world.effect.MobEffectInstance, net.minecraft.client.gui.Gui, com.mojang.blaze3d.vertex.PoseStack, int, int, float, float)'
im on forge 47.0.3 because its compatible with optifine but it works on all forges from 1.20 to 1.20.1