"Missing or invalid PHY"

“Missing of Invalid PHY”

I’ve seen this error a couple times now, and it’s completely un-intuitive/non-descriptive.

What does this mean, and where is the documentation for this error ?

It’s a broken link to something, usually a graphic.

That would be a notice about a missing thumbnail image. If you have a graphic resource like HDPosterURL or SDPosterURL set to anything beside ‘invalid’, or to an inaccessible url then you will get those. It could also be reported for the overhang url images or some other image, but typically it will be a thumbnail graphic.