Layout definition. "You must supply a layout_width attribute."

i think u have not put dp after width size .what why your code might not be working. ex android:layout_weight="20" use this android:layout_weight="20dp"

Nope all of your TextViews have layout_height and layout_weight instead of layout_height and layout_width (and possibly layout_weight). Try this:

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

    <LinearLayout 
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:orientation="horizontal"
        android:weightSum="100" >

    <TextView android:id="@+id/nombreEvento"
        android:layout_height="fill_parent"
        android:layout_width="0dp"
        android:layout_weight="70"
    />

    <TextView android:id="@+id/moneda"
        android:layout_height="fill_parent"
        android:layout_width="0dp"
        android:layout_weight="10"
    />

    <TextView android:id="@+id/totalEvento"
        android:layout_height="wrap_content"
        android:layout_width="0dp"
        android:layout_weight="20"
    />
    </LinearLayout>

<TextView android:id="@+id/fecha"
    android:layout_width="fill_parent"
    android:layout_height="wrap_content"
/>

</LinearLayout>

Try adding android:layout_width="wrap_content" to your TextViews that do not have it.