If you have a normal map that is part of or for a UVmapped, sculpted object, it should apply via 'import normal map' just fine. 

You can also load a normal map on a terrain or Vue primitive, metablob etc if you load it as a layer. If you do so just straight up, you'll get the error message about UVs.

Though I've not shown anything in the galleries (too busy building content) I've been playing with normals since V9. They aren't all that and a bag of chips.

They are cool no doubt and look great if executed well. What made me drop them in favor of old fashioned bump and highlight was that, in the function editor, the normal map takes over and you can't mix it with anything without headache. 

My new kit Cliffhangers was at first using only normals....but because of the limitations, I did the whole kit over and dropped the normals....

M