I have created a 2 photo gallery and using "preview" or
Direct Link to Your Gallery
Use this URL when linking to your PowerGallery from any web page:
Embed in PHP Page
Insert the following code within an existing PHP page, exactly where you wish this PowerGallery to display:
$pg_id = '1';
$pg_theme = 'light';
in order to check it and getting server errrors.
I did the 777 to 755. I've reset the galleries images folders from 777 to 755. All other folders checked and show as 755.
The link to the test page is using the php include. That page doesn't show the core layout of the gallery, but if you click in the middle, the lightbox does reveal itself. I was showing it in case there is a clue here as to what is going on.