It sounds like the problem might be with the paths to your images.
Please check that your image and thumbnail files have been uploaded to the correct location on your web server and make sure that the imageURL and thumbURL entries in your gallery's XML file point correctly to the images.

Please also see this FAQ:
My images show locally, but not when I upload them to my website. Why?

Another possible cause of your problem might be with permissions. Please check that the permissions on the image and thumbnail files (and on the 'images' and 'thumbs' folders) are not too restrictive. Default permissions of 755 for folders and 644 for files should work fine.
You can check permissions on files and folders on your web server with an FTP program such as Filezilla or by using the File Manager within your web hosting account's online cPanel.

I hope these suggestions help.
However, if you continue to experience difficulties, then please post (or email me) the URL to your gallery's web page so that I can take a look at the problem for myself and hopefully help further.
Thank you.

You can add a languageList into the Pro Options text area of a gallery's settings window (or the Pro Options text area of the Set Defaults section of the Manage Galleries page) as follows (changing the values as necessary):

languageList="Show Thumbnails|Hide Thumbnails|Expand Gallery|Close Gallery|Open Image in New Window|Images"

(The Pro Options text area will accept any configuration options not catered for via individual controls in the plugin's interface.)

'juicebox_pro.lrwebengine' is a folder, rather than a file (as you noted), although it is seen as a special package on a Mac which can be double-clicked to install. On a Windows PC, you will need to follow the Manual Installation instructions on the plugin's support page.

Just copy the 'juicebox.lrwebengine' folder to your Lightroom 'Web Galleries' folder and the web engine will be accessible via Lightroom's Web module.

• Mac OS X - Users/username/Library/Application Support/Adobe/Lightroom/Web Galleries/

• Windows Vista, 7, 8, 8.1, 10 - C:\Users\username\AppData\Roaming\Adobe\Lightroom\Web Galleries\

• Windows XP - C:\Documents and Settings\username\Application Data\Adobe\Lightroom\Web Galleries\

You're welcome.

Unfortunately, there is currently no version of the 'juicebox.js' file which does not contain jQuery and there is no way for a user to remove jQuery from the 'juicebox.js' file. (Incidentally, the version of jQuery bundled within the 'juicebox.js' file is a simplified version rather than the complete library.)

Removing jQuery from the 'juicebox.js' file would require that the user includes jQuery in their web page.
This might be easy enough for yourself but it would be another step in the embedding process and we try to keep the embedding instructions as simple as possible. Also, there is the risk that the user would include an incompatible version of jQuery. As it stands, Juicebox will work with any (or no) version of jQuery loaded into the web page.
Also, if the simplified version of jQuery was removed from the 'juicebox.js' file (Juicebox essentially becoming a jQuery plugin) and the full version of jQuery was loaded into the web page alongside the slimmed-down 'juicebox.js' file, then the total size of both JavaScript files would exceed the current size of the 'juicebox.js' file alone.
This would be a benefit only for those users who already load jQuery into their web page.

Having said that, the developers have been looking into ways to minimize the 'juicebox.js' file.

Also, I would also encourage you to post your suggestion in the Feature Requests forum thread. This keeps all the ideas together and ensures that they are not overlooked. Thank you.

Unfortunately, Juicebox-Pro was not designed with the intention that users could access and use internal classes so what you are doing is not officially supported. It just happens to be the only way I could think of for you to achieve your goal.
It looks like the onImageChange() function (which signifies that a new image has been selected) does not wait for the container with class .jb-dt-main-image-0 to be present in the DOM before being fired and so the only solution I was able to come up with was a short delay. As the delay seems to be necessary only for the very first image in the gallery, you could perhaps change the code so that the delay is used only once, when the gallery is loaded.

// Initialize counter
var counter = 0;

jb.onImageChange = function(e) {

// Set delay only on first image change
var delay = counter === 0 ? 200 : 0;

    // Introduce short delay to ensure required class is present in Document Object Model
    window.setTimeout(function() {

        // The internal image index used for dynamically-generated classes starts at zero so subtract 1 from public image index
        var index = e.id - 1;

        // Form CSS class for currently-displayed image
        var element = '.jb-dt-main-image-' + index;

        // Get URL of currently-displayed image from src attribute of <img> tag
        var src = $(element).find('img').first().attr('src');

        // Extract Flickr photoId from URL
        var id = src.substring(src.lastIndexOf('/') + 1, src.indexOf('_'));

        // Fetch tags of currently-displayed image using Flickr API flickr.tags.getListPhoto method
        // Enter your own Flickr API Key in the line below
        $.getJSON('https://api.flickr.com/services/rest/?method=flickr.tags.getListPhoto&api_key={your_flickr_api_key}&photo_id=' + id + '&format=json&jsoncallback=?', function(json) {

            // Initialize tags array
            var tags = [];

            // Iterate over all tags
            $.each(json.photo.tags.tag, function(i, data) {

                // Add new tag to array
                tags.push(data.raw);

            });

            // Display tags array in output container
            $("#output").html('<p>Tags: ' + (tags.length > 0 ? tags : 'None') + '</p>');

        }).fail(function() {

            // Fail message
            $("#output").html('<p>Cannot find tags.</p>');

        });
    }, delay);

    // Increment counter
    counter++;

};

Edit:
On further investigation, it looks like the Juicebox-Pro API method getImageInfo() returns the thumbURL successfully (but not the imageURL) so you should be able to extract the Flickr photoId from the thumbURL as follows. This avoids the need for any delay at all.

jb.onImageChange = function(e) {

    // Get image info for current image
    var info = jb.getImageInfo(e.id);

    // Get thumbURL for current image
    var src = info.thumbURL;

    // Extract Flickr photoId from thumbURL
    var id = src.substring(src.lastIndexOf('/') + 1, src.indexOf('_'));

    // Fetch tags of currently-displayed image using Flickr API flickr.tags.getListPhoto method
    // Enter your own Flickr API Key in the line below
    $.getJSON('https://api.flickr.com/services/rest/?method=flickr.tags.getListPhoto&api_key={your_flickr_api_key}&photo_id=' + id + '&format=json&jsoncallback=?', function(json) {

        // Initialize tags array
        var tags = [];

        // Iterate over all tags
        $.each(json.photo.tags.tag, function(i, data) {

            // Add new tag to array
            tags.push(data.raw);

        });

        // Display tags array in output container
        $("#output").html('<p>Tags: ' + (tags.length > 0 ? tags : 'None') + '</p>');

    }).fail(function() {

        // Fail message
        $("#output").html('<p>Cannot find tags.</p>');

    });
};

I have logged a bug report with the developers regarding the inability to fetch the imageURL from the getImageInfo() method when using Flickr as a source of images.

No problem. If you no longer have the 'juicebox_pro_1.4.4.zip' file or your purchase email (with the download link), just fill in this Download Link Request Form to the best of your ability and we'll send you a new link.

Keep the link for future use as it will allow you to download new versions of Juicebox-Pro when they are released. Upgrades are free within the same major version number and the download link will always point towards the latest version rather than the version you purchased. Full details can be found on the Upgrading Juicebox support page.

I do not know what might be causing this (the ability to swipe to navigate should obviously be consistent across all images).
Just a thought but maybe the controls on the image overlay (or perhaps even the image overlay itself) is somehow interfering with the swipe gesture.
Try setting showImageOverlay="NEVER" (in JuiceboxBuilder-Pro's 'Customize -> Main Image' section) to see if this makes a difference. If it helps, then you could maybe disable the autohide for the image overlay by setting inactivityTimeout="0" ('Customize -> Main Image') or allow the user to toggle the overlay on or off using the Info Button by setting showInfoButton="TRUE" ('Customize -> Button Bar').

onImageChange() is fired for the first image in the gallery but the initial search for the '.jb-dt-main-image-0' class might be happening before the element is present in the Document Object Model (DOM). Introducing a short delay (with setTimeout()) before searching for the '.jb-dt-main-image-0' class should work.
Try the following (which introduces a 100ms delay):

jb.onImageChange = function(e) {

    // Introduce short delay to ensure required class is present in Document Object Model
    window.setTimeout(function() {

        // The internal image index used for dynamically-generated classes starts at zero so subtract 1 from public image index
        var index = e.id - 1;

        // Form CSS class for currently-displayed image
        var element = '.jb-dt-main-image-' + index;

        // Get URL of currently-displayed image from src attribute of <img> tag
        var src = $(element).find('img').first().attr('src');

        // Extract Flickr photoId from URL
        var id = src.substring(src.lastIndexOf('/') + 1, src.indexOf('_'));

        // Fetch tags of currently-displayed image using Flickr API flickr.tags.getListPhoto method
        // Enter your own Flickr API Key in the line below
        $.getJSON('https://api.flickr.com/services/rest/?method=flickr.tags.getListPhoto&api_key={your_flickr_api_key}&photo_id=' + id + '&format=json&jsoncallback=?', function(json) {

            // Initialize tags array
            var tags = [];

            // Iterate over all tags
            $.each(json.photo.tags.tag, function(i, data) {

                // Add new tag to array
                tags.push(data.raw);

            });

            // Display tags array in output container
            $("#output").html('<p>Tags: ' + (tags.length > 0 ? tags : 'None') + '</p>');

        }).fail(function() {

            // Fail message
            $("#output").html('<p>Cannot find tags.</p>');

        });
    }, 100);
};

No, sorry. However, I found the following quote on this Flickr help page: https://www.flickr.com/services/api/auth.spec.html

I hope this points you in the right direction.
These pages might also help:
User Authentication - https://www.flickr.com/services/api/auth.oauth.html
JavaScript Libraries for OAuth - http://oauth.net/code/ (scroll down to JavaScript section)

Please check the following:
(1) After saving changes to the 'C:\Program Files (x86)\JuiceboxBuilder-Pro\template\index.html' file, re-open the file in a text editor to ensure that the changes are still there.
(2) After creating or re-saving a gallery with JuiceboxBuilder-Pro, check that the gallery's 'index.html' file includes the modifications you made.
(3) After uploading the new 'index.html' file to your web server, be sure to clear your browser's cache before reloading your web page.

If you have problems with (1) or (2) above, then make sure that the '\template\index.html' file is not read-only ('Right-Click -> Properties') and try turning off VirtualStore in Windows. (Windows may be creating a copy of your modified file in a VirtualStore location but JuiceboxBuilder-Pro needs to read the file from its original location.)
Try a web search with terms such as 'disable virtualstore windows' for instructions.

If you are in any doubt that your old file is not being overwritten with the new version, then delete the old version from your web server first before uploading the new version in its place.

I hope this helps.

You're welcome!
I hope your project goes well.

Do you perhaps have AdBlock installed?
There is a known bug whereby images can flicker when loading in Safari with AdBlock installed when imageTransitionType="CROSS_FADE".
The developers are aware of this bug and hopefully it will be fixed in a future version.
In the meantime, workarounds would be to change the imageTransitionType or uninstall AdBlock (although uninstalling AdBlock would work only for your own computer and not for potential visitors to your site who also use the combination of Safari and AdBlock).

If you are not using AdBlock and this is not the cause of your problem, then please let me know and I will investigate further.
Thank you.

You can force the Screen Mode (via the screenMode configuration option) but it is not possible to force the Input Mode (although, if a touch-screen device is detected, you should be able to control the gallery with touch gestures).

This is something that you might need to look into independently of Juicebox. (It is not something that would be directly integrated with the gallery itself.)
Windows 8.1 has a built-in on-screen touch keyboard which can be enabled to appear automatically when an input field is selected in an app (though not in a desktop browser). This should work OK in Chrome when launched as an app.

(Incidentally, I have modified my code above to store the tags in an array which might be more useful if you need to refer to them later.)