Thanks for getting back so quickly!
After having the XML error message cover the screen 15 times or more in LR 6, primarily while moving sliders, sometimes just entering figures for the sliders and pressing the return key, I gave up. Another problem was after the navigation buttons disappeared, the Caption bar stayed there and never left.
I launched Lightroom 5 and it worked without a single problem! The only small issue I found was that the main image drop shadow didn't seem to change, regardless of the settings. Otherwise, I was pleased with how everything was working, the caption disappeared properly with the other navigation, etc., which is a nice feature, and came back with a mouse over, as it should, and did in the free version.
I realize these problems can be difficult to track down, especially if no one else is reporting them. I'll let you know if and when I go back to LR 6 and I'll write down a few things.
For fine art photography, this stuff has to work, and work well, or visitors, sometimes important visitors, leave the site. I'll be embedding these galleries, which also worked well.
Thanks for your efforts. I'll add a few ideas in the improvement/suggestions thread. Just what you need...
Best,
Byron