title: Cannot switch activities in Android except one activity
body: <p>So I have been making a simple four button app for my IT 1 class and have been having a problem with some code. I have four buttons that are supposed to call a startActivity and change to a different screen. The first button, labeled fire, works perfectly fine and works 100% of the time. The next button, labeled Earthquake doesn't work, even though the code is the same (without the parts that need to change). The other 2 buttons also do not work. I have tried making a new project, copying the working xml, copying the exact code. I cannot figure out why it doesn't work. </p>
  
  <p>MainActivity XML</p>
  
  <pre><code>&lt;?xml version="1.0" encoding="utf-8"?&gt;
  &lt;RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
  xmlns:tools="http://schemas.android.com/tools"
  android:layout_width="match_parent"
  android:layout_height="match_parent"
  android:background="#81848b"
  android:paddingBottom="@dimen/activity_vertical_margin"
  android:paddingLeft="@dimen/activity_horizontal_margin"
  android:paddingRight="@dimen/activity_horizontal_margin"
  android:paddingTop="@dimen/activity_vertical_margin"
  tools:context="com.example.carrieowen.testproject.MainActivity"&gt;
  
  &lt;LinearLayout
      android:orientation="vertical"
      android:layout_width="match_parent"
      android:layout_height="match_parent"
      android:weightSum="1"
      android:layout_alignParentTop="true"
      android:layout_alignParentRight="true"
      android:layout_alignParentEnd="true"&gt;
  
      &lt;TextView
          android:id="@+id/myText"
          android:layout_width="match_parent"
          android:layout_height="wrap_content"
          android:textColor="#eff2f9"
          android:text="Emergency Drills"
          android:gravity="center"
          android:textSize="32sp"
          /&gt;
  
      &lt;Button
          android:layout_width="fill_parent"
          android:layout_height="wrap_content"
          android:layout_marginTop="10dp"
          android:padding="40dp"
          android:text="Fire"
          android:background="#e71e1e"
          android:id="@+id/button"
          android:onClick="Fire"/&gt;
  
      &lt;Button
          android:layout_width="fill_parent"
          android:layout_height="wrap_content"
          android:layout_marginTop="10dp"
          android:background="#009c12"
          android:padding="40dp"
          android:text="Earthquake"
          android:id="@+id/button2"
          android:onClick="Earthquake"/&gt;
  
      &lt;Button
          android:layout_width="fill_parent"
          android:layout_height="wrap_content"
          android:layout_marginTop="10dp"
          android:background="#eef035"
          android:padding="40dp"
          android:text="Tornado"
          android:id="@+id/button3"
          android:onClick="Tornado"/&gt;
  
      &lt;Button
          android:layout_width="fill_parent"
          android:layout_height="wrap_content"
          android:layout_marginTop="10dp"
          android:background="#1b4fdd"
          android:padding="40dp"
          android:text="Code Blue"
          android:id="@+id/button4"
          android:onClick="CodeBlue"/&gt;
  
  &lt;/LinearLayout&gt;
  &lt;/RelativeLayout&gt;
  </code></pre>
  
  <p>The MainActivity Java</p>
  
  <pre><code>package com.example.carrieowen.testproject;
  
  import android.content.Intent;
  import android.support.v7.app.AppCompatActivity;
  import android.os.Bundle;
  import android.view.View;
  import android.widget.LinearLayout;
  
  public class MainActivity extends AppCompatActivity {
  
      @Override
      public void onCreate(Bundle savedInstanceState) {
          super.onCreate(savedInstanceState);
          setContentView(R.layout.activity_main);
      }
  
  
      public void Fire (View view){
          Intent changeScreenFire = new Intent(this, firescreen.class);
          startActivity(changeScreenFire);
      }
  
      public void Earthquake (View view){
      Intent changeScreenEarthquake = new Intent(this, earthquake.class);
      startActivity(changeScreenEarthquake);
      }
      public void Tornado (View view){
          Intent changeScreenTornado = new Intent(this, tornado.class);
          startActivity(changeScreenTornado);
      }
      public void CodeBlue (View view){
          Intent changeScreenCodeBlue = new Intent(this, codeblue.class);
          startActivity(changeScreenCodeBlue);
      }
  
  }
  </code></pre>
  
  <p>The FireScreen Java</p>
  
  <pre><code>package com.example.carrieowen.testproject;
  
  import android.support.v7.app.AppCompatActivity;
  import android.os.Bundle;
  
  public class firescreen extends AppCompatActivity {
  
      @Override
      protected void onCreate(Bundle savedInstanceState) {
          super.onCreate(savedInstanceState);
          setContentView(R.layout.activity_firescreen);
      }
  }
  </code></pre>
  
  <p>The Earthquake Java</p>
  
  <pre><code>package com.example.carrieowen.testproject;
  
  import android.support.v7.app.AppCompatActivity;
  import android.os.Bundle;
  
  public class earthquake extends AppCompatActivity {
  
      @Override
      protected void onCreate(Bundle savedInstanceState) {
          super.onCreate(savedInstanceState);
          setContentView(R.layout.activity_earthquake);
      }
  }
  </code></pre>
  
  <p>The XML for the Fire and Earthquake are the same other than the Text boxes being different. If needed will add.</p>