errors trying get MessageAdapter to work

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="wrap_content">

    <ImageView
        android:id="@+id/msgIcon"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentLeft="true"
        android:layout_alignParentTop="true"
        android:paddingLeft="@dimen/activity_horizontal_margin"
        android:paddingTop="@dimen/message_list_item_vertical_margin"
      />

    <TextView
        android:id="@+id/senderLabel"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:paddingLeft="@dimen/activity_horizontal_margin"
        android:paddingTop="@dimen/message_list_item_vertical_margin"
        android:textAppearance="?android:attr/textAppearanceMedium" />

</RelativeLayout>

package com.benbasha.sedu;

import java.util.List;

import android.content.Context;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ArrayAdapter;
import android.widget.ImageView;
import android.widget.TextView;

import com.parse.ParseObject;



public class MsgAdapter extends ArrayAdapter<ParseObject> {

    protected Context mContext;
    protected List<ParseObject> mMsg;

    public MsgAdapter(Context context, List<ParseObject> messages) {
        super(context, R.layout.message_item, messages);
        mContext = context;
        mMsg = messages;
    }

    @Override
    public View getView(int position, View convertView, ViewGroup parent) {

        ViewHolder holder;

        if (convertView == null) {
            convertView = LayoutInflater.from(mContext).inflate(R.layout.message_item, null);
            holder = new ViewHolder();
            holder.iconImageView = (ImageView) convertView.findViewById(R.id.msgIcon);
            holder.nameLabel = (TextView) convertView.findViewById(R.id.senderLabel);
            convertView.setTag(holder);
        } else {
            holder = (ViewHolder) convertView.getTag();
        }

        ParseObject msg = mMsg.get(position);

        if (msg.getString(Constants.KEY_FILE_TYPE).equals(Constants.TYPE_VIDEO))
            holder.iconImageView.setImageResource(R.drawable.ic_action_picture);
        else 
            holder.iconImageView.setImageResource(R.drawable.ic_action_camera);
        holder.nameLabel.setText(msg.getString(Constants.KEY_SENDER_NAME));

        return convertView;
    }

    private static class ViewHolder {
        ImageView iconImageView;
        TextView nameLabel;
    }
}

06-05 22:33:58.431: E/AndroidRuntime(1621): FATAL EXCEPTION: main
06-05 22:33:58.431: E/AndroidRuntime(1621): Process: com.benbasha.sedu, PID: 1621
06-05 22:33:58.431: E/AndroidRuntime(1621): android.view.InflateException: Binary XML file line #6: Error inflating class <unknown>
06-05 22:33:58.431: E/AndroidRuntime(1621):     at android.view.LayoutInflater.createView(LayoutInflater.java:620)
06-05 22:33:58.431: E/AndroidRuntime(1621):     at com.android.internal.policy.impl.PhoneLayoutInflater.onCreateView(PhoneLayoutInflater.java:56)
06-05 22:33:58.431: E/AndroidRuntime(1621):     at android.view.LayoutInflater.onCreateView(LayoutInflater.java:669)
06-05 22:33:58.431: E/AndroidRuntime(1621):     at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:694)
06-05 22:33:58.431: E/AndroidRuntime(1621):     at android.view.LayoutInflater.rInflate(LayoutInflater.java:755)
06-05 22:33:58.431: E/AndroidRuntime(1621):     at android.view.LayoutInflater.inflate(LayoutInflater.java:492)
06-05 22:33:58.431: E/AndroidRuntime(1621):     at android.view.LayoutInflater.inflate(LayoutInflater.java:397)
06-05 22:33:58.431: E/AndroidRuntime(1621):     at android.view.LayoutInflater.inflate(LayoutInflater.java:353)
06-05 22:33:58.431: E/AndroidRuntime(1621):     at com.benbasha.sedu.MsgAdapter.getView(MsgAdapter.java:34)
06-05 22:33:58.431: E/AndroidRuntime(1621):     at android.widget.AbsListView.obtainView(AbsListView.java:2263)
06-05 22:33:58.431: E/AndroidRuntime(1621):     at android.widget.ListView.makeAndAddView(ListView.java:1790)
06-05 22:33:58.431: E/AndroidRuntime(1621):     at android.widget.ListView.fillDown(ListView.java:691)
06-05 22:33:58.431: E/AndroidRuntime(1621):     at android.widget.ListView.fillFromTop(ListView.java:752)
06-05 22:33:58.431: E/AndroidRuntime(1621):     at android.widget.ListView.layoutChildren(ListView.java:1630)
06-05 22:33:58.431: E/AndroidRuntime(1621):     at android.widget.AbsListView.onLayout(AbsListView.java:2091)
06-05 22:33:58.431: E/AndroidRuntime(1621):     at android.view.View.layout(View.java:14817)
06-05 22:33:58.431: E/AndroidRuntime(1621):     at android.view.ViewGroup.layout(ViewGroup.java:4631)
06-05 22:33:58.431: E/AndroidRuntime(1621):     at android.widget.RelativeLayout.onLayout(RelativeLayout.java:1055)
06-05 22:33:58.431: E/AndroidRuntime(1621):     at android.view.View.layout(View.java:14817)
06-05 22:33:58.431: E/AndroidRuntime(1621):     at android.view.ViewGroup.layout(ViewGroup.java:4631)
06-05 22:33:58.431: E/AndroidRuntime(1621):     at android.widget.FrameLayout.layoutChildren(FrameLayout.java:453)
06-05 22:33:58.431: E/AndroidRuntime(1621):     at android.widget.FrameLayout.onLayout(FrameLayout.java:388)
06-05 22:33:58.431: E/AndroidRuntime(1621):     at android.view.View.layout(View.java:14817)
06-05 22:33:58.431: E/AndroidRuntime(1621):     at android.view.ViewGroup.layout(ViewGroup.java:4631)
06-05 22:33:58.431: E/AndroidRuntime(1621):     at android.support.v4.view.ViewPager.onLayout(ViewPager.java:1589)
06-05 22:33:58.431: E/AndroidRuntime(1621):     at android.view.View.layout(View.java:14817)
06-05 22:33:58.431: E/AndroidRuntime(1621):     at android.view.ViewGroup.layout(ViewGroup.java:4631)
06-05 22:33:58.431: E/AndroidRuntime(1621):     at android.widget.FrameLayout.layoutChildren(FrameLayout.java:453)
06-05 22:33:58.431: E/AndroidRuntime(1621):     at android.widget.FrameLayout.onLayout(FrameLayout.java:388)
06-05 22:33:58.431: E/AndroidRuntime(1621):     at android.view.View.layout(View.java:14817)
06-05 22:33:58.431: E/AndroidRuntime(1621):     at android.view.ViewGroup.layout(ViewGroup.java:4631)
06-05 22:33:58.431: E/AndroidRuntime(1621):     at com.android.internal.widget.ActionBarOverlayLayout.onLayout(ActionBarOverlayLayout.java:374)
06-05 22:33:58.431: E/AndroidRuntime(1621):     at android.view.View.layout(View.java:14817)
06-05 22:33:58.431: E/AndroidRuntime(1621):     at android.view.ViewGroup.layout(ViewGroup.java:4631)
06-05 22:33:58.431: E/AndroidRuntime(1621):     at android.widget.FrameLayout.layoutChildren(FrameLayout.java:453)
06-05 22:33:58.431: E/AndroidRuntime(1621):     at android.widget.FrameLayout.onLayout(FrameLayout.java:388)
06-05 22:33:58.431: E/AndroidRuntime(1621):     at android.view.View.layout(View.java:14817)
06-05 22:33:58.431: E/AndroidRuntime(1621):     at android.view.ViewGroup.layout(ViewGroup.java:4631)
06-05 22:33:58.431: E/AndroidRuntime(1621):     at android.view.ViewRootImpl.performLayout(ViewRootImpl.java:1987)
06-05 22:33:58.431: E/AndroidRuntime(1621):     at android.view.ViewRootImpl.performTraversals(ViewRootImpl.java:1744)
06-05 22:33:58.431: E/AndroidRuntime(1621):     at android.view.ViewRootImpl.doTraversal(ViewRootImpl.java:1000)
06-05 22:33:58.431: E/AndroidRuntime(1621):     at android.view.ViewRootImpl$TraversalRunnable.run(ViewRootImpl.java:5670)
06-05 22:33:58.431: E/AndroidRuntime(1621):     at android.view.Choreographer$CallbackRecord.run(Choreographer.java:761)
06-05 22:33:58.431: E/AndroidRuntime(1621):     at android.view.Choreographer.doCallbacks(Choreographer.java:574)
06-05 22:33:58.431: E/AndroidRuntime(1621):     at android.view.Choreographer.doFrame(Choreographer.java:544)
06-05 22:33:58.431: E/AndroidRuntime(1621):     at android.view.Choreographer$FrameDisplayEventReceiver.run(Choreographer.java:747)
06-05 22:33:58.431: E/AndroidRuntime(1621):     at android.os.Handler.handleCallback(Handler.java:733)
06-05 22:33:58.431: E/AndroidRuntime(1621):     at android.os.Handler.dispatchMessage(Handler.java:95)
06-05 22:33:58.431: E/AndroidRuntime(1621):     at android.os.Looper.loop(Looper.java:136)
06-05 22:33:58.431: E/AndroidRuntime(1621):     at android.app.ActivityThread.main(ActivityThread.java:5017)
06-05 22:33:58.431: E/AndroidRuntime(1621):     at java.lang.reflect.Method.invokeNative(Native Method)
06-05 22:33:58.431: E/AndroidRuntime(1621):     at java.lang.reflect.Method.invoke(Method.java:515)
06-05 22:33:58.431: E/AndroidRuntime(1621):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:779)
06-05 22:33:58.431: E/AndroidRuntime(1621):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:595)
06-05 22:33:58.431: E/AndroidRuntime(1621):     at dalvik.system.NativeStart.main(Native Method)
06-05 22:33:58.431: E/AndroidRuntime(1621): Caused by: java.lang.reflect.InvocationTargetException
06-05 22:33:58.431: E/AndroidRuntime(1621):     at java.lang.reflect.Constructor.constructNative(Native Method)
06-05 22:33:58.431: E/AndroidRuntime(1621):     at java.lang.reflect.Constructor.newInstance(Constructor.java:423)
06-05 22:33:58.431: E/AndroidRuntime(1621):     at android.view.LayoutInflater.createView(LayoutInflater.java:594)
06-05 22:33:58.431: E/AndroidRuntime(1621):     ... 54 more
06-05 22:33:58.431: E/AndroidRuntime(1621): Caused by: java.lang.UnsupportedOperationException: Can't convert to dimension: type=0x1
06-05 22:33:58.431: E/AndroidRuntime(1621):     at android.content.res.TypedArray.getDimensionPixelSize(TypedArray.java:464)
06-05 22:33:58.431: E/AndroidRuntime(1621):     at android.view.View.<init>(View.java:3569