java - Android Intent not starting activity -

i'm having issues getting startactivity(intent) open next activity. when press associated button it's printing string debug console, new activity isn't starting. doing wrong.

public class mainactivity extends appcompatactivity {  @override protected void oncreate(bundle savedinstancestate) {     super.oncreate(savedinstancestate);     setcontentview(r.layout.activity_main);     toolbar toolbar = (toolbar) findviewbyid(r.id.toolbar);     setsupportactionbar(toolbar);      button cambtn = (button) findviewbyid(r.id.btncamera);     cambtn.setonclicklistener(new view.onclicklistener(){         @override         public void onclick(view view){             startcameraoption(view);         }     });  }  public void startcameraoption(view view){     intent intent = new intent(mainactivity.this, cameraoption.class);     intent.putextra("launcher","launched.");     system.out.println("starting next activity,");     startactivity(intent); } } 

there's mainactivity.

here manifest.

<?xml version="1.0" encoding="utf-8"?> <manifest xmlns:android="http://schemas.android.com/apk/res/android"     package="com.google.sample.cloudvision">      <uses-permission android:name="android.permission.internet" />     <uses-permission android:name="android.permission.read_external_storage"/>     <uses-permission android:name="android.permission.camera"/>     <uses-permission android:name="android.permission.write_external_storage" />       <application         android:allowbackup="true"         android:icon="@mipmap/ic_launcher"         android:label="@string/app_name"         android:supportsrtl="true"         android:theme="@style/apptheme">         <activity             android:screenorientation="portrait"             android:name="com.google.sample.cloudvision.mainactivity"             android:label="@string/app_name"             android:theme="@style/apptheme.noactionbar">             <intent-filter>                 <action android:name="android.intent.action.main" />                 <category android:name="android.intent.category.launcher" />             </intent-filter>         </activity>         <activity             android:name=".cameraoption">         </activity>         <activity             android:name=".picturechosenclass">         </activity>     </application>  </manifest> 

per comments need change cameraoptions extend appcompatactivity or activity instead of mainactivity