This error means you forget to add android word before any attribute in xml file.
For example-
id="@+id/my_location"
You need to write android before id
like below.
android:id="@+id/my_location"
Your code is perfect. But "skip" in component_constraints appears to be ignored. I had to manually add place holder to the layout to "fill in" empty spots. I tried "skip 1" and that also had no impact.
For more information see following link.