java.util.ConcurrentModificationException: null java.util.ConcurrentModificationException: null at java.util.ArrayList$ArrayListSpliterator.forEachRemaining(ArrayList.java:1388) ~[?:1.8.0_202] at java.util.stream.ReferencePipeline$Head.forEach(ReferencePipeline.java:580) ~[?:1.8.0_202] at net.minecraft.server.world.ServerLightingProvider.method_17312(ServerLightingProvider.java:135) ~[minecraft-1.16.4-projectmapped-net.fabricmc.yarn-1.16.4+build.7-v2.jar:?] at net.minecraft.server.world.ServerLightingProvider.runTasks(ServerLightingProvider.java:170) ~[minecraft-1.16.4-projectmapped-net.fabricmc.yarn-1.16.4+build.7-v2.jar:?] at net.minecraft.server.world.ServerLightingProvider.method_17313(ServerLightingProvider.java:108) ~[minecraft-1.16.4-projectmapped-net.fabricmc.yarn-1.16.4+build.7-v2.jar:?] at net.minecraft.server.world.ChunkTaskPrioritySystem.method_17634(ChunkTaskPrioritySystem.java:58) ~[minecraft-1.16.4-projectmapped-net.fabricmc.yarn-1.16.4+build.7-v2.jar:?] at net.minecraft.util.thread.TaskExecutor.runNext(TaskExecutor.java:94) ~[minecraft-1.16.4-projectmapped-net.fabricmc.yarn-1.16.4+build.7-v2.jar:?] at net.minecraft.util.thread.TaskExecutor.runWhile(TaskExecutor.java:137) ~[minecraft-1.16.4-projectmapped-net.fabricmc.yarn-1.16.4+build.7-v2.jar:?] at net.minecraft.util.thread.TaskExecutor.run(TaskExecutor.java:105) ~[minecraft-1.16.4-projectmapped-net.fabricmc.yarn-1.16.4+build.7-v2.jar:?]