DH crashing out on 1.21.8

[DH-PriorityTaskPicker Thread[7]/ERROR]: Uncaught exception in thread "DH-PriorityTaskPicker Thread[7]"
java.util.concurrent.RejectedExecutionException: Task com.seibel.distanthorizons.core.util.threading.PriorityTaskPicker$TrackedRunnable@3e696bd3 rejected from com.seibel.distanthorizons.core.util.threading.RateLimitedThreadPoolExecutor@71eb9bf7[Running, pool size = 4, active threads = 4, queued tasks = 4, completed tasks = 4]