This bug has now been fixed in v1.4.1. Please see the Upgrading Juicebox support page for details.

In order to upgrade JuiceboxBuilder-Pro, it is necessary to first uninstall any existing version.
Please try the tips in the Installation Issues section of the JuiceboxBuilder User Guide.
Hopefully this will help.

Implementing the above (to have a lightbox open to display an image when it is clicked) into galleries created by WP-Juicebox can be done but would require quite a bit of work as the plugin does not have any built-in lightbox-style functionality, does not have interface support for linkURL or linkTarget and the embedding code that the plugin provides would have to be modified to include the custom JavaScript code required.

(1) Install and activate WP-Juicebox.
(2) Upgrade WP-Juicebox to Juicebox-Pro following the instructions here (required for setting imageClickMode="OPEN_URL" and for using the Juicebox-Pro API).
(3) Install and activate the Shadowbox JS plugin (and download the Shadowbox source files from within the plugin's settings page).
(4) Open the 'wp-juicebox/config.php' file in a plain text editor and change all three instances (on lines 47, 74 and 98) of:

$image_element->setAttribute('linkURL', $image_url);

... to:

$image_element->setAttribute('linkURL', 'javascript: func();');

(5) Also, in the same file, change all three instances (on lines 48, 75 and 99) of:

$image_element->setAttribute('linkTarget', '_blank');

... to:

$image_element->setAttribute('linkTarget', '_self');

(6) Open the 'wp-juicebox/wp-juicebox.php' file in a plain text editor and change lines 240-251 (the $string_builder section) to the following:

$string_builder = '<!--START JUICEBOX EMBED-->' . PHP_EOL;
$string_builder .= '<script type="text/javascript">' . PHP_EOL;
$string_builder .= '    var jb;' . PHP_EOL;
$string_builder .= '    jQuery(document).ready(function () {' . PHP_EOL;
$string_builder .= '        jb = new juicebox({' . PHP_EOL;
$string_builder .= '            backgroundColor: "' . $background_color . '",' . PHP_EOL;
$string_builder .= '            configUrl: "' . $config_url . '",' . PHP_EOL;
$string_builder .= '            containerId: "juicebox-container-' . $gallery_id . '",' . PHP_EOL;
$string_builder .= '            galleryHeight: "' . $gallery_height . '",' . PHP_EOL;
$string_builder .= '            galleryWidth: "' . $gallery_width . '"' . PHP_EOL;
$string_builder .= '        });' . PHP_EOL;
$string_builder .= '    });' . PHP_EOL;
$string_builder .= '    function func() {' . PHP_EOL;
$string_builder .= '        var index = jb.getImageIndex();' . PHP_EOL;
$string_builder .= '        var info = jb.getImageInfo(index);' . PHP_EOL;
$string_builder .= '        var url = info.imageURL;' . PHP_EOL;
$string_builder .= '        var title = info.title;' . PHP_EOL;
$string_builder .= '        Shadowbox.open({' . PHP_EOL;
$string_builder .= '            content: url,' . PHP_EOL;
$string_builder .= '            player: "img",' . PHP_EOL;
$string_builder .= '            title: title' . PHP_EOL;
$string_builder .= '        });' . PHP_EOL;
$string_builder .= '    }' . PHP_EOL;
$string_builder .= '</script>' . PHP_EOL;
$string_builder .= '<div id="juicebox-container-' . $gallery_id . '"></div>' . PHP_EOL;
$string_builder .= '<!--END JUICEBOX EMBED-->' . PHP_EOL;

(7) Enter imageClickMode="OPEN_URL" in the Pro Options text area of your gallery's settings window.

Please note that the procedure above has not been tested extensively and I cannot vouch for the robustness of the solution or the stability of WP-Juicebox itself after making these modifications.
However, I hope it help and at least points you in the right direction.

[The line numbers above refer to the current version of WP-Juicebox (v1.4.0.1).]

When using a Picasa Web Album as the source of image, WP-Juicebox uses the Picasa image 'title' as the Juicebox image title (which by default is the image filename) and the Picasa image 'summary' as the Juicebox image caption.

If you want to prevent WP-Juicebox from displaying the Picasa image 'title', please do the following.
(1) Open the 'wp-juicebox/config.php' file in a plain text editor.
(2) Change line 101 from:

$title_text = $dom_doc->createCDATASection($attachment->title);

... to:

$title_text = $dom_doc->createCDATASection('');

Please note that the line number above refers to the current version of WP-Juicebox (v1.4.0.1).

On a single monitor, when useFullScreenExpand="TRUE", it is not possible to move the cursor outside an expanded gallery so that the overlay fades out.
One possible alternative would be to set showInfoButton="TRUE" (in JuiceboxBuilder-Pro's 'Customize -> Button Bar' section) and you can then toggle the overlay on and off using the Info Button on the Button Bar. The Button Bar will be displayed on screen all the time (allowing access to the Info Button) but all other components on the overlay (for example the caption area and the main image navigation buttons) will be toggled on and off.

The XML file used for the http://sandbox.castarchitecture.com/pro … homes.html gallery is not the one you quoted.
The gallery uses this XML file which does not set the two configuration options from my post above: http://sandbox.castarchitecture.com/pro … config.xml

If you want your gallery to use the http://sandbox.castarchitecture.com/TEM … config.xml file, then you can point towards it in your gallery's embedding code using a configURL configuration option or, alternatively, as your 'TEMP_JUICEBOX_FOLDER' folder seems to be a complete gallery folder, you can use a baseUrl, for example:

<!--START JUICEBOX EMBED-->
<script src="/TEMP_JUICEBOX_FOLDER/jbcore/juicebox.js"></script>
<script>
    new juicebox({
        baseUrl: '/TEMP_JUICEBOX_FOLDER/jbcore/classic/theme.css',
        containerId: 'juicebox-container',
        galleryWidth: '100%',
        galleryHeight: '100%',
        backgroundColor: 'rgba(255,255,255,1)'
    });
</script>
<div id="juicebox-container">
</div>
<!--END JUICEBOX EMBED-->

If you do not specify either a configUrl or a baseUrl, Juicebox will look for a file named 'config.xml' in the same directory as the page containing the embedding code. In your case, there is such an XML file in that location but it is not the XML you want your gallery to use.
(Alternatively, you could replace the http://sandbox.castarchitecture.com/pro … /config.xm file with http://sandbox.castarchitecture.com/TEM … config.xml on your web server.)

@Tiphaine

On JuiceboxBuilder-Pro's 'Images' tab, you can select multiple images (using Ctrl+Click and/or Shift+Click) and then delete the selection using the 'Images -> Delete' option from the drop-down menu at the top (Ctrl+D).

Please see the Multiple Galleries on One HTML Page example in the Embedding Multiple Galleries support section. You can view the source of the web page in your browser and copy/modify it to suit your own needs.

Essentially, you would keep each gallery in its own separate folder (to avoid the risk of duplicate file names in the same directory), upload the complete gallery folders to your web server and embed the galleries in your web page using the baseUrl method of embedding as documented here.

If you run into any problems, please post the URL top your web page so that I can take a look and help further.

For reference (and others reading this post), instructions for installing the Juicebox plugin for Lightroom can be found here.

It sounds like your 'juicebox.lrwebengine' folder may be in an incorrect location. (You are certainly looking in the right place in the Lightroom interface. Once installed, 'Juicebox' should be displayed as an option in the 'Web -> Layout Style' section.)
As you are using a Mac, you should be able to just double-click the 'juicebox.lrwebengine' package to install the plugin (rather than manually copying it to the correct folder). Please note that this will not work for Windows users.

There are also instructions for installing Web Engines (such as the Juicebox plugin for Lightroom) here (with instructions on how to access hidden folders if necessary to find the correct path).

Hopefully the information above will help.

@Bchristensen

It is no longer possible to have the shared image's thumbnail displayed in the pop-up share window due to limitations imposed by Facebook on what data can be passed via their share URL. Only one thumbnail can be used per gallery. (The link will still point towards the correct image within your gallery, though.)

The image used in the Facebook sharing pop-up window can be set using an Open Graph og:image <meta> tag in the <head> section of your web page, such as the following:

<meta property="og:image" content="http://www.example.com/images/thumbnail.jpg" />

If you create a gallery with JuiceboxBuilder-Pro, an og:image tag will be automatically generated and included in the gallery's 'index.html' file. If you are embedding your gallery in an existing web page alongside other content, then you will need to add an og:image tag manually.

Twitter does not use a thumbnail image in its sharing pop-up window. Twitter shares only text (the gallery title, the image title and the image caption) and a link (to the specific image in your gallery).

The 'full.html' file is used to display the gallery when it is expanded in a new page, either when expandInNewPage="TRUE" or when expandInNewPage="AUTO" and Juicebox determines that the configuration option should be TRUE (such as when the gallery is displayed on iOS devices). Please see the Expand Gallery Behavior support section for more information.
Please note that expanding in a new page will work only when the gallery has been uploaded to a web server.

If your gallery does not expand correctly on your iPad (showing a blank screen), then please post the URL to your gallery so that I can take a look and help further.

As long as you can view your gallery in a browser using either the http:// or https:// protocol, the expand in new page functionality should work OK.