Blocks Not Appearing in MT App inventor

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1

I am creating an MIT App invertor project.
My Requirement is actually very simple. I need a UUID to be generation.

I used the online IDE and the code is really simple

the below code compiles beautifully generates the aix file.
I am also able to include in my project.

the problem is when i click on the uuid generation block . i am expecting the functions to be listed. whcih i can use. but nothing apears

can you help ?

package com.nepa.uuidgen;

import android.app.Activity;
import android.content.Context;
import com.google.appinventor.components.annotations.*;
import com.google.appinventor.components.common.ComponentCategory;
import com.google.appinventor.components.runtime.AndroidNonvisibleComponent;
import com.google.appinventor.components.runtime.ComponentContainer;
import com.google.appinventor.components.runtime.EventDispatcher;
import java.util.UUID;

@DesignerComponent(
        version = 1,
        description = "this generates uuid",
        category = ComponentCategory.EXTENSION,
        nonVisible = true,
        iconName = "")

@SimpleObject(external = true)
//Libraries
@UsesLibraries(libraries = "")
//Permissions
@UsesPermissions(permissionNames = "")

public class uuid_gen extends AndroidNonvisibleComponent {

    //Activity and Context
    private Context context;
    private Activity activity;

    public uuid_gen(ComponentContainer container){
        super(container.$form());
        this.activity = container.$context();
        this.context = container.$context();
    }

    @SimpleFunction(description = "return uuid")
    public String GetUUID(){
        return UUID.randomUUID().toString();
    }

    @SimpleEvent(description = "Test Event Generated by Niotron")
    public void TestEvent(){
        EventDispatcher.dispatchEvent(this, "TestEvent");
    }
}