[11:33:04] [User Authenticator #1/INFO]: UUID of player Ji_Qi is 4d6c34cf-d1d5-3abe-ad09-02dcc36cfd1c
[11:33:09] [Server thread/WARN]: java.lang.ArrayIndexOutOfBoundsException: 0
[11:33:09] [Server thread/WARN]:         at me.AdityaTD.TitleWelcomeMessage.TitlesAPI.sendTitle(TitlesAPI.java:57)
[11:33:09] [Server thread/WARN]:         at me.AdityaTD.TitleWelcomeMessage.TWM.send(TWM.java:64)
[11:33:09] [Server thread/WARN]:         at me.AdityaTD.TitleWelcomeMessage.TWM.onJoin(TWM.java:49)
[11:33:09] [Server thread/WARN]:         at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
[11:33:09] [Server thread/WARN]:         at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
[11:33:09] [Server thread/WARN]:         at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
[11:33:09] [Server thread/WARN]:         at java.lang.reflect.Method.invoke(Unknown Source)
[11:33:09] [Server thread/WARN]:         at org.bukkit.plugin.java.JavaPluginLoader$1.execute(JavaPluginLoader.java:301)
[11:33:09] [Server thread/WARN]:         at org.bukkit.plugin.RegisteredListener.callEvent(RegisteredListener.java:62)
[11:33:09] [Server thread/WARN]:         at org.bukkit.plugin.SimplePluginManager.fireEvent(SimplePluginManager.java:502)
[11:33:09] [Server thread/WARN]:         at org.bukkit.plugin.SimplePluginManager.callEvent(SimplePluginManager.java:487)
[11:33:09] [Server thread/WARN]:         at net.minecraft.server.v1_8_R1.PlayerList.onPlayerJoin(PlayerList.java:263)
[11:33:09] [Server thread/WARN]:         at net.minecraft.server.v1_8_R1.PlayerList.a(PlayerList.java:148)
[11:33:09] [Server thread/WARN]:         at net.minecraft.server.v1_8_R1.LoginListener.b(LoginListener.java:109)
[11:33:09] [Server thread/WARN]:         at net.minecraft.server.v1_8_R1.LoginListener.c(LoginListener.java:41)
[11:33:09] [Server thread/WARN]:         at net.minecraft.server.v1_8_R1.NetworkManager.a(NetworkManager.java:159)
[11:33:09] [Server thread/WARN]:         at net.minecraft.server.v1_8_R1.ServerConnection.c(ServerConnection.java:82)
[11:33:09] [Server thread/WARN]:         at net.minecraft.server.v1_8_R1.MinecraftServer.z(MinecraftServer.java:785)
[11:33:09] [Server thread/WARN]:         at net.minecraft.server.v1_8_R1.DedicatedServer.z(DedicatedServer.java:316)
[11:33:09] [Server thread/WARN]:         at net.minecraft.server.v1_8_R1.MinecraftServer.y(MinecraftServer.java:623)
[11:33:09] [Server thread/WARN]:         at net.minecraft.server.v1_8_R1.MinecraftServer.run(MinecraftServer.java:526)
[11:33:09] [Server thread/WARN]:         at java.lang.Thread.run(Unknown Source)
[11:33:10] [Server thread/INFO]: Ji_Qi[/127.0.0.1:53440] logged in with entity id 482 at ([world] 108.67362923528256, 70.0, 246.35624318440694)
[11:33:29] [Async Chat Thread - #0/INFO]: Ji_Qi >> .

出现报错后服务器出现什么问题了吗？如果没有什么问题，也不要怎么管。有时候服务器就会这样子，不影响正常使用就好

这种报错很正常的，你问也问不出个所以然，只要他不一直刷屏，不影响游戏就好了！