Why is Android Studio reporting "URI is not registered"?

For me this was because I was using a debug and release build variant. I added the new folders src/debug/res/layout/some_layout.xml file manually, and it didn't recognize the URI. I switched the build variant to release, and then back to debug. This caused Android Studio to reload something, and the error went away.

EDIT: Also check that you have the correct filename. I had this issue again by adding a debug AndroidManifest.xml, but mistakenly named it AndroidManifest.xml.xml.

You are having this issue because you are at the wrong destination! The correct directory for the Layout resource file has to be under "res-layout" not "res-all-layout"

I use Intellij IDEA but I think it will also work in Android Studio, can you see the "Event Log" at IDE right bottom corner, did it have some message like that "Android framework is detected in the project Configure", that means you should have a framework configuration. If so, just follow the message link.
In the same way, you can go to "File > Project Structure > Modules" , and then add a Android Facet.

by the way, if I want use a customized namespace like you do, I'll write the resource identifier as my package name as I define the AndroidManifest.xml package attribute of the manifest element, below is my code.

<manifest package="com.my.name.android">
    ...
</manifest>

<RelativeLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/apk/res/com.my.name.android">
</RelativeLayout>

Hope this helps you.