Follow this template except for feature requests. Use pastebin when providing /protocol dump and any relevant errors.

Make sure you've done the following:

• [V] You're using the latest build for your server version
• [V] This isn't an issue caused by another plugin
• [V] You've checked for duplicate issues
• [V] You didn't use /reload

Debug paste link:
https://hastebin.com/iqikodanew.pl

Description and relevant errors:
`---- Minecraft Crash Report ----
// Daisy, daisy...

Time: 31/05/19 14:49
Description: Ticking entity

java.lang.ClassCastException: java.lang.Integer cannot be cast to java.util.Optional
at air.dv(SourceFile:2783)
at air.aa(SourceFile:285)
at ais.aa(SourceFile:226)
at aii.h(SourceFile:390)
at air.h(SourceFile:2046)
at ais.h(SourceFile:293)
at auv.h(SourceFile:132)
at dhn.a(SourceFile:165)
at bhi.a(SourceFile:676)
at dhn.d(SourceFile:134)
at cvk.m(SourceFile:1433)
at cvk.e(SourceFile:925)
at cvk.b(SourceFile:411)
at net.minecraft.client.main.Main.main(SourceFile:154)

package fr.cocoraid.prodigygui.nms.wrapper.living;

import fr.cocoraid.prodigygui.utils.VersionChecker;
import org.bukkit.Location;
import org.bukkit.entity.Player;

public class WrapperEntitySlime extends WrappedEntityLiving {
public WrapperEntitySlime(Location location, Player player) {

    super(location,player, VersionChecker.isLowerOrEqualThan(VersionChecker.v1_13_R2) ? 65 : 67);

}
public void setSize(int size) {
   if(VersionChecker.isLowerOrEqualThan(VersionChecker.v1_13_R2)) 
        setDataWatcherObject(Integer.class, 12, size); //this code is working fine with 1.13.2
   else {
        //what to use instead  for 1.4.2 ?
    }
}

}
`