The new ItemJoin version (3.5) doesn't work with the 1.8.8 version of Spigot. The error doesn't appear at startup. It appear when a player join the server or change the world. Seeing the error, I think it is because of the new Tipped Arrows feature, it is loading even if the server isn't using 1.9/1.10 version of Spigot.

PlayerJoinEvent error:

[17:46:24] [Server thread/ERROR]: Could not pass event PlayerJoinEvent to ItemJoin v3.5
org.bukkit.event.EventException
at org.bukkit.plugin.java.JavaPluginLoader$1.execute(JavaPluginLoader.java:310) ~[spigot-1.8.8.jar:git-Spigot-e4d4710-e1ebe52]
at org.bukkit.plugin.RegisteredListener.callEvent(RegisteredListener.java:62) ~[spigot-1.8.8.jar:git-Spigot-e4d4710-e1ebe52]
at org.bukkit.plugin.SimplePluginManager.fireEvent(SimplePluginManager.java:502) [spigot-1.8.8.jar:git-Spigot-e4d4710-e1ebe52]
at org.bukkit.plugin.SimplePluginManager.callEvent(SimplePluginManager.java:487) [spigot-1.8.8.jar:git-Spigot-e4d4710-e1ebe52]
at net.minecraft.server.v1_8_R3.PlayerList.onPlayerJoin(PlayerList.java:298) [spigot-1.8.8.jar:git-Spigot-e4d4710-e1ebe52]
at net.minecraft.server.v1_8_R3.PlayerList.a(PlayerList.java:157) [spigot-1.8.8.jar:git-Spigot-e4d4710-e1ebe52]
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[?:1.8.0_91]
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source) ~[?:1.8.0_91]
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source) ~[?:1.8.0_91]
at java.lang.reflect.Method.invoke(Unknown Source) ~[?:1.8.0_91]
at nul.goto. ..... .final..lIIlIllllI.abstract(AutoIn_GotoFinal) [AutoIn17-18_obf.jar:?]
at nul.goto. ..... .final..IIlIlIllIl.abstract(AutoIn_GotoFinal) [AutoIn17-18_obf.jar:?]
at nul.goto. ..... .final..IIIIlIIlll.abstract(AutoIn_GotoFinal) [AutoIn17-18_obf.jar:?]
at nul.goto. ..... .final..IIlIllIIIl.b(AutoIn_GotoFinal) [AutoIn17-18_obf.jar:?]
at net.minecraft.server.v1_8_R3.LoginListener.c(LoginListener.java:54) [spigot-1.8.8.jar:git-Spigot-e4d4710-e1ebe52]
at nul.goto. ..... .final..IIlIllIIIl.c(AutoIn_GotoFinal) [AutoIn17-18_obf.jar:?]
at net.minecraft.server.v1_8_R3.NetworkManager.a(NetworkManager.java:231) [spigot-1.8.8.jar:git-Spigot-e4d4710-e1ebe52]
at net.minecraft.server.v1_8_R3.ServerConnection.c(ServerConnection.java:148) [spigot-1.8.8.jar:git-Spigot-e4d4710-e1ebe52]
at net.minecraft.server.v1_8_R3.MinecraftServer.B(MinecraftServer.java:814) [spigot-1.8.8.jar:git-Spigot-e4d4710-e1ebe52]
at net.minecraft.server.v1_8_R3.DedicatedServer.B(DedicatedServer.java:374) [spigot-1.8.8.jar:git-Spigot-e4d4710-e1ebe52]
at net.minecraft.server.v1_8_R3.MinecraftServer.A(MinecraftServer.java:654) [spigot-1.8.8.jar:git-Spigot-e4d4710-e1ebe52]
at net.minecraft.server.v1_8_R3.MinecraftServer.run(MinecraftServer.java:557) [spigot-1.8.8.jar:git-Spigot-e4d4710-e1ebe52]
at java.lang.Thread.run(Unknown Source) [?:1.8.0_91]
Caused by: java.lang.NoSuchFieldError: TIPPED_ARROW
at me.RockinChaos.itemjoin.CacheItems.CacheItems.run(CacheItems.java:79) ~[?:?]
at me.RockinChaos.itemjoin.Listeners.JoinItem.JoinItem.giveOnJoin(JoinItem.java:53) ~[?:?]
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[?:1.8.0_91]
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source) ~[?:1.8.0_91]
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source) ~[?:1.8.0_91]
at java.lang.reflect.Method.invoke(Unknown Source) ~[?:1.8.0_91]
at org.bukkit.plugin.java.JavaPluginLoader$1.execute(JavaPluginLoader.java:306) ~[spigot-1.8.8.jar:git-Spigot-e4d4710-e1ebe52]
... 22 more

PlayerChangedWorldEvent error:

[17:51:55] [Server thread/ERROR]: Could not pass event PlayerChangedWorldEvent to ItemJoin v3.5
org.bukkit.event.EventException
at org.bukkit.plugin.java.JavaPluginLoader$1.execute(JavaPluginLoader.java:310) ~[spigot-1.8.8.jar:git-Spigot-e4d4710-e1ebe52]
at org.bukkit.plugin.RegisteredListener.callEvent(RegisteredListener.java:62) ~[spigot-1.8.8.jar:git-Spigot-e4d4710-e1ebe52]
at org.bukkit.plugin.SimplePluginManager.fireEvent(SimplePluginManager.java:502) [spigot-1.8.8.jar:git-Spigot-e4d4710-e1ebe52]
at org.bukkit.plugin.SimplePluginManager.callEvent(SimplePluginManager.java:487) [spigot-1.8.8.jar:git-Spigot-e4d4710-e1ebe52]
at net.minecraft.server.v1_8_R3.PlayerList.moveToWorld(PlayerList.java:628) [spigot-1.8.8.jar:git-Spigot-e4d4710-e1ebe52]
at org.bukkit.craftbukkit.v1_8_R3.entity.CraftPlayer.teleport(CraftPlayer.java:471) [spigot-1.8.8.jar:git-Spigot-e4d4710-e1ebe52]
at org.bukkit.craftbukkit.v1_8_R3.entity.CraftEntity.teleport(CraftEntity.java:226) [spigot-1.8.8.jar:git-Spigot-e4d4710-e1ebe52]
at com.onarandombox.MultiverseCore.utils.SimpleSafeTTeleporter.safelyTeleport(SimpleSafeTTeleporter.java:216) [Multiverse-Core-2.4.jar:?]
at com.onarandombox.MultiverseCore.commands.TeleportCommand.runCommand(TeleportCommand.java:159) [Multiverse-Core-2.4.jar:?]
at com.pneumaticraft.commandhandler.multiverse.CommandHandler.checkAndRunCommand(CommandHandler.java:279) [Multiverse-Core-2.4.jar:?]
at com.pneumaticraft.commandhandler.multiverse.CommandHandler.processFoundCommands(CommandHandler.java:143) [Multiverse-Core-2.4.jar:?]
at com.pneumaticraft.commandhandler.multiverse.CommandHandler.locateAndRunCommand(CommandHandler.java:93) [Multiverse-Core-2.4.jar:?]
at com.onarandombox.MultiverseCore.MultiverseCore.onCommand(MultiverseCore.java:476) [Multiverse-Core-2.4.jar:?]
at org.bukkit.command.PluginCommand.execute(PluginCommand.java:44) [spigot-1.8.8.jar:git-Spigot-e4d4710-e1ebe52]
at org.bukkit.command.SimpleCommandMap.dispatch(SimpleCommandMap.java:141) [spigot-1.8.8.jar:git-Spigot-e4d4710-e1ebe52]
at org.bukkit.craftbukkit.v1_8_R3.CraftServer.dispatchCommand(CraftServer.java:641) [spigot-1.8.8.jar:git-Spigot-e4d4710-e1ebe52]
at net.minecraft.server.v1_8_R3.PlayerConnection.handleCommand(PlayerConnection.java:1162) [spigot-1.8.8.jar:git-Spigot-e4d4710-e1ebe52]
at net.minecraft.server.v1_8_R3.PlayerConnection.chat(PlayerConnection.java:1078) [spigot-1.8.8.jar:git-Spigot-e4d4710-e1ebe52]
at org.bukkit.craftbukkit.v1_8_R3.entity.CraftPlayer.chat(CraftPlayer.java:237) [spigot-1.8.8.jar:git-Spigot-e4d4710-e1ebe52]
at com.gmail.filoghost.chestcommands.internal.icon.command.OpIconCommand.execute(OpIconCommand.java:17) [ChestCommands.jar:?]
at com.gmail.filoghost.chestcommands.internal.CommandsClickHandler.onClick(CommandsClickHandler.java:34) [ChestCommands.jar:?]
at com.gmail.filoghost.chestcommands.api.Icon.onClick(Icon.java:319) [ChestCommands.jar:?]
at com.gmail.filoghost.chestcommands.internal.icon.ExtendedIcon.onClick(ExtendedIcon.java:243) [ChestCommands.jar:?]
at com.gmail.filoghost.chestcommands.task.ExecuteCommandsTask.run(ExecuteCommandsTask.java:21) [ChestCommands.jar:?]
at org.bukkit.craftbukkit.v1_8_R3.scheduler.CraftTask.run(CraftTask.java:71) [spigot-1.8.8.jar:git-Spigot-e4d4710-e1ebe52]
at org.bukkit.craftbukkit.v1_8_R3.scheduler.CraftScheduler.mainThreadHeartbeat(CraftScheduler.java:350) [spigot-1.8.8.jar:git-Spigot-e4d4710-e1ebe52]
at net.minecraft.server.v1_8_R3.MinecraftServer.B(MinecraftServer.java:723) [spigot-1.8.8.jar:git-Spigot-e4d4710-e1ebe52]
at net.minecraft.server.v1_8_R3.DedicatedServer.B(DedicatedServer.java:374) [spigot-1.8.8.jar:git-Spigot-e4d4710-e1ebe52]
at net.minecraft.server.v1_8_R3.MinecraftServer.A(MinecraftServer.java:654) [spigot-1.8.8.jar:git-Spigot-e4d4710-e1ebe52]
at net.minecraft.server.v1_8_R3.MinecraftServer.run(MinecraftServer.java:557) [spigot-1.8.8.jar:git-Spigot-e4d4710-e1ebe52]
at java.lang.Thread.run(Unknown Source) [?:1.8.0_91]
Caused by: java.lang.NoSuchFieldError: TIPPED_ARROW
at me.RockinChaos.itemjoin.CacheItems.CacheItems.run(CacheItems.java:79) ~[?:?]
at me.RockinChaos.itemjoin.Listeners.JoinItem.ChangedWorld.giveFirstJoinOnWorldChanged(ChangedWorld.java:69) ~[?:?]
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[?:1.8.0_91]
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source) ~[?:1.8.0_91]
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source) ~[?:1.8.0_91]
at java.lang.reflect.Method.invoke(Unknown Source) ~[?:1.8.0_91]
at org.bukkit.plugin.java.JavaPluginLoader$1.execute(JavaPluginLoader.java:306) ~[spigot-1.8.8.jar:git-Spigot-e4d4710-e1ebe52]
... 30 more

Confirmed bug and this has been fixed for ItemJoin v3.6. The update with this fix will be coming out today.

Fixed as of v3.6 and can be downloaded here; https://www.spigotmc.org/resources/itemjoin.12661/download?version=107393

I tested it on v1.8.8 and it works flawlessly for me. This should be the fix you are looking for :).

If you have any other problems feel free to open another issue.

More Info: In my items.yml I have been removed the tipped arrow example.