I have a very simple EditText, as follows:
I had the same problem. In my case, I had applied the parent="android:Theme.Light" to values-V14/styles.xml. This made the EditText control to look like a control from android API 2.3.3 and below. But the error message text was all white and hence, was not visible. After some head scratching I figured this out.
Change the parent="android:Theme.Light" to parent="android:Theme.Holo.Light.NoActionBar" (what ever Holo theme). But in the EditText definition add android:background="@android:drawable/edit_text"
My EditText looks like this