Vixio Error

[17:05:30 WARN]: Exception in thread "Craft Scheduler Thread - 1021"
[17:05:30 WARN]: org.apache.commons.lang.UnhandledException: Plugin Vixio v2.0.0-pre-2 generated an exception while executing task 60705
        at org.bukkit.craftbukkit.v1_8_R3.scheduler.CraftAsyncTask.run(CraftAsyncTask.java:56)
        at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
        at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
        at java.lang.Thread.run(Thread.java:748)
Caused by: net.dv8tion.jda.core.exceptions.ErrorResponseException: 10008: Unknown Message
        at net.dv8tion.jda.core.exceptions.ErrorResponseException.create(ErrorResponseException.java:148)
        at net.dv8tion.jda.core.requests.Request.onFailure(Request.java:91)
        at net.dv8tion.jda.core.entities.MessageChannel$1.handleResponse(MessageChannel.java:900)
        at net.dv8tion.jda.core.requests.Request.handleResponse(Request.java:178)
        at net.dv8tion.jda.core.requests.Requester.execute(Requester.java:202)
        at net.dv8tion.jda.core.requests.Requester.execute(Requester.java:112)
        at net.dv8tion.jda.core.requests.Requester.execute(Requester.java:95)
        at net.dv8tion.jda.core.requests.ratelimit.BotRateLimiter$Bucket.run(BotRateLimiter.java:312)
        at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
        at java.util.concurrent.FutureTask.run(FutureTask.java:266)
        at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.access$201(ScheduledThreadPoolExecutor.java:180)
        at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:293)
        at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
        at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
        at net.dv8tion.jda.core.requests.RateLimiter$RateLimitThreadFactory.lambda$newThread$0(RateLimiter.java:129)
        ... 1 more