I have duplicated the single.php file and renamed it single-test.php.
I have added:
Template Name Posts: Test
at the top of the file and after it's saved, I'm still getting "This theme has no available custom post templates.". Why???
I have a fresh install of wp and I have tried everything including reinstalling wp and the theme and still the same message!
Any, and I mean any help would earn you my lifelong, undying gratitude.