Solved Why doesn't this work?

Hi! So I am trying to do a plugin to give speed every 10 seconds and it gives me an error. :/

Code:

package alabingu.guanaffaop.threads;

import org.bukkit.Bukkit;
import org.bukkit.entity.Player;

public class Speed implements Runnable {

    @Override
    public void run() {
        while(true) {
          
            for(Player all : Bukkit.getOnlinePlayers()) {
                all.performCommand("effect @a speed 11 1");
            }
          
            try {
                Thread.sleep(10000);
            } catch(InterruptedException e) {
              
            }
          
        }
      
    }
  
}

Error:

Code:

[08:27:25 WARN]: Unknown CommandBlock failed to handle command
java.lang.IllegalStateException: Asynchronous effect add!
        at org.spigotmc.AsyncCatcher.catchOp(AsyncCatcher.java:14) ~[spigot-1.8.8.jar:git-Spigot-21fe707-e1ebe52]
        at net.minecraft.server.v1_8_R3.EntityLiving.addEffect(EntityLiving.java:582) ~[spigot-1.8.8.jar:git-Spigot-21fe707-e1ebe52]
        at net.minecraft.server.v1_8_R3.CommandEffect.execute(SourceFile:97) ~[spigot-1.8.8.jar:git-Spigot-21fe707-e1ebe52]
        at org.bukkit.craftbukkit.v1_8_R3.command.VanillaCommandWrapper.dispatchVanillaCommand(VanillaCommandWrapper.java:93) [spigot-1.8.8.jar:git-Spigot-21fe707-e1ebe52]
        at org.bukkit.craftbukkit.v1_8_R3.command.VanillaCommandWrapper.execute(VanillaCommandWrapper.java:43) [spigot-1.8.8.jar:git-Spigot-21fe707-e1ebe52]
        at org.bukkit.command.SimpleCommandMap.dispatch(SimpleCommandMap.java:141) [spigot-1.8.8.jar:git-Spigot-21fe707-e1ebe52]
        at org.bukkit.craftbukkit.v1_8_R3.CraftServer.dispatchCommand(CraftServer.java:641) [spigot-1.8.8.jar:git-Spigot-21fe707-e1ebe52]
        at org.bukkit.craftbukkit.v1_8_R3.entity.CraftPlayer.performCommand(CraftPlayer.java:242) [spigot-1.8.8.jar:git-Spigot-21fe707-e1ebe52]
        at alabingu.guanaffaop.threads.Speed.run(Speed.java:13) [GuanaFFAOP.jar:?]
        at java.lang.Thread.run(Thread.java:745) [?:1.8.0_112]

 

But I've never used that, could you give me an example, please? :v @timtower

 

Ok, thx DD