android - Error: Suspicious namespace and prefix combination [NamespaceTypo] when I try create Signed APK

Question

I Googled my problem but I can't find a solution.
When I try to create a signed APK, I get this error:

 Error:(6) Error: Suspicious namespace and prefix combination [NamespaceTypo]
               ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   Explanation for issues of type "NamespaceTypo":
   track these down.
   xmlns:app="http://schemas.android.com/tools"
   obscure error messages. This check looks for potential misspellings to help
   Accidental misspellings in namespace declarations can lead to some very

This is the fragment of this layout file:

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:fab="http://schemas.android.com/apk/res-auto"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    xmlns:app="http://schemas.android.com/tools"
    app:layout_behavior="@null"
    android:layout_gravity="bottom|right">

Answer 1

change the code xmlns:app="http://schemas.android.com/tools" with this:

xmlns:app="http://schemas.android.com/apk/res-auto"

It made mine work.