There are no configuration options that could be used to achieve this but it could be done with JavaScript as follows.

<script type="text/javascript" src="jbcore/juicebox.js"></script>
<script type="text/javascript">

    var a, b, c;
    var thresholdWidth = 700;
    var tracker = false;

    function loadGallery(a, b, c) {
        new juicebox({
            containerId: "juicebox-container",
            maxThumbColumns: a,
            maxThumbRows: b,
            thumbsPosition: c
        });
        tracker = true;
    }

    function thumbsStatus() {
        var windowWidth = window.innerWidth ? window.innerWidth : $(window).width();
        if (windowWidth < thresholdWidth && (c === 'LEFT' || tracker === false)) {
            a = '10'; // maxThumbRows
            b = '1'; // maxThumbColumns
            c = 'BOTTOM'; // thumbsPosition
            loadGallery(a, b, c);
        }
        if (windowWidth >= thresholdWidth && (c === 'BOTTOM' || tracker === false)) {
            a = '3'; // maxThumbRows
            b = '3'; // maxThumbColumns
            c = 'LEFT'; // thumbsPosition
            loadGallery(a, b, c);
        }
    }

    $(document).ready(function() {
        thumbsStatus();
        $(window).resize(thumbsStatus);
    });

</script>

I hope this helps.

The order of preference that the Download Button uses is as follows.
It will use the linkURL if it exists. If there is no linkURL, then it will use the largeImageUrl. If there is no largeImageUrl, it will use the imageUrl.
The linkURL is first in preference to allow custom files associated with the images (such as .pdf or .zip files) to be downloaded instead of the images themselves.

That's really the concept behind a Multi-Size Image gallery (that larger images are displayed on larger resolution screens).

It sounds like you're looking to have a single-size image gallery but also have larger images available for download.
Assuming you are allowing JuicboxBuilder to resize your source images and want to use the source images for the Download Button, then this could be achieved as follows.

(1) Create a regular single-size image gallery with JuiceboxBuilder, allowing the application to use the same values for the imageURLs and the linkURLs (which is the default behavior).

(2) Copy your source images (the ones you fed to JuiceboxBuilder to create the gallery) into a new empty folder named 'originals' and place this folder into your gallery folder (alongside the 'images' folder).

(3) Edit your gallery's 'config.xml' file and change all instances of linkURL="images/ to linkURL="originals/.
If you use a text editor such as Notepad++ (free), you can change all instances in a single global search and replace action. It should take less than a minute to edit the file from start to finish.

I hope this helps.

If you are looking to do something with Juicebox that is not currently possible, please feel free to post your ideas in the Feature Requests forum thread.
This keeps all the ideas together and ensures that they are not overlooked by the developers.
Thank you.

Unfortunately, there is a known bug in JuiceboxBuilder whereby an error can be generated if the resize image dimensions are too large.
The exact dimensions can vary depending on the source images but, under certain circumstances, JuiceboxBuilder can fail (displaying the error message you quoted) if 'Max Width' and 'Max Height' are both greater than 2364.
However, the developers are aware of this issue and are currently investigating it.
Hopefully it will be fixed in a future version.

The password protection functionality requires server-side code (PHP) and works only when the gallery has been uploaded to a web sever.
Please see the Password Protection support section for details.

You could use an image title such as the following (lowercase 'L' in Wingdings is the character you are looking for).

<span style="font-family: Wingdings; font-size: 24px; color: #ff0000;">l</span>

However, this will display as intended only in Microsoft browsers (Edge and Internet Explorer) and only if Wingdings is installed on the user's computer.

It would be much better to use a Unicode character so that it can be seen correctly in all browsers.
You can display a Unicode character in a web page using its decimal code or hexadecimal code.

Please see this web page for a table of Windings characters and their Unicode equivalents. Look for the lowercase 'L' in the first column in the table for the Unicode codes you'll need to use.
You can use either of the following in an image title to display a big red dot.

Decimal:

<span style="font-size: 24px; color: #ff0000;">&#9679;</span>

Hexadecimal:

<span style="font-size: 24px; color: #ff0000;">&#x25CF;</span>

Please also see this FAQ regarding using HTML formatting in image titles and captions.
How do I add HTML formatting to image captions and titles?

You can download the latest version of WP-Juicebox (v1.5.0) from the plugin's support page here. (WP-Juicebox is not included in the Juicebox-Pro zip package.)
Install the plugin following the Installation Instructions (in the link above) and upgrade it to Juicebox-Pro (using the 'jbcore' folder from your Juicebox-Pro v1.5.0 zip package) by following the Upgrading to Juicebox-Pro instructions.

Essentially:
(1) Download WP-Juicebox v1.5.0.
(2) Replace the plugin's 'jbcore' folder with the one from your Juicebox-Pro v1.5.0 zip package.
(3) Upload the 'wp-juicebox' folder to your WordPress 'wp-content/plugins/' directory, overwriting your existing 'wp-juicebox' folder.

After doing this, you will have the latest version of both WP-Juicebox and Juicebox-Pro.

It looks like the problem is with your Picasa User Id and/or Picasa Album Name.

Check that the functionality is working OK by setting up a test gallery with the following information:
Picasa User Id: picasateam
Picasa Album Name: VegasWeekend

Please check your Picasa User Id. It may not be your email address.
Also, as Google have discontinued Picasa and are moving all Picasa web albums over to Google+ photo albums, you might need to enter Google credentials rather than Picasa ones.

You can find your Google User Id by logging in to Google+ and clicking the 'Google+ Profile' link above the 'My Account' button (after clicking your custom image at the top right). Your Google User Id will be the 21 digit number in the URL (in your browser's address bar).

Take a look at this forum thread which should hopefully point you in the right direction towards finding your Google Album Id (a 19 digit number).

I hope this helps.

You're welcome.
I'm glad you've got it working.

PHP 5.4.35.

Have you tried my 3 suggestions above yet to see if any of them make a difference?

Creating Juicebox galleries with WP-Juicebox v1.5.0 and NextGEN v2.1.43 seems to work OK on my own server with WordPress 4.5.2 (and PHP 5.4.35) so the problem may somehow be related to your own setup (your current theme, activated plugins, PHP version, server settings).

Unfortunately, as I am currently unable to replicate the problem, it makes troubleshooting quite difficult.

I would certainly try reverting to a default WordPress theme and deactivating all plugins (including all CDN and caching plugins) other that WP-Juicebox and NextGEN to see if this helps.

The captionPosition in this gallery is BELOW_IMAGE.
The Info Button only toggles elements positioned on the overlay (captionPosition="OVERLAY" or captionPosition="OVERLAY_IMAGE").
When captionPosition is BELOW_IMAGE, BOTTOM or BELOW_THUMBS, the captions will always be visible (and not toggled via the Info Button).

When I go directly to http://fotoslubna.com/wp-content/plugin … lery_id=55 in a browser, I see the complete XML data.

Are you using a Content Delivery Network or any server side caching?
Try temporarily disabling any CDN and caching plugins to see if this makes a difference.

The problem is that your gallery files are not in the correct location on your web server.
According to the embedding code on your 'new616.html' page, your gallery's 'juicebox.js' file should be located here: http://www.annabrahms.com/jbcore/juicebox.js
However, going directly to that location in a browser results in an error 404 (file not found).

If you are following the regular embedding instructions here, then you'll need to copy the contents of your gallery folder into the same directory as the web page containing the embedding code (in your case, your root directory, alongside the 'new616.html' page).

If you have already uploaded the complete gallery folder to your web server somewhere, then you can use the baseUrl method of embedding as documented here.

If you continue to experience difficulties, please let me know where on your web server your gallery files are and I should be able to help with what embedding code to use.