Thank you for the links to your galleries.

I see that you are using a custom PHP file (named 'config.php')  to dynamically generate your gallery's XML data.
The problem lies somewhere within this file (which is not part of the Juicebox package).
There is something within this file that is not compatible with PHP 7.2 onwards.

Unfortunately, I do not have access to your 'config.php' file to inspect its code but opening it directly in a browser reveals the following warning:

Your use of the PHP count() function (whatever it may be) on line 10 is listed in the 'Backward incompatible changes' on the 'Migrating from PHP 7.1.x to PHP 7.2.x' support page here.

In order for your 'config.php' file to be compatible with PHP 7.2 onwards, you'll need to find a new PHP method to count whatever it is that you are counting.

I hope this points you in the right direction.
If you continue to experience difficulties, then please zip and upload your 'config.php' file somewhere (and provide a download link) so that I can inspect the code and hopefully help further.
Thank you.

Yes. Please see the following link for details: Using an External jbcore Folder

Essentially, you can upload a single instance of the 'jbcore' folder to anywhere you like on your web server and then load the 'juicebox.js' file from within this folder at the start of each gallery's embedding code. (Details are in the link above.)

This has the added advantage of allowing you to upgrade all your galleries at once (when new versions of Juicebox are released) by just replacing a single 'jbcore' folder.

You're welcome!

I don't know what is causing your problem but I do not think that it is a coincidence that the two images that do not display have the keyword "hidden" in their titles.
I have tried setting flickrShowTitle="FALSE" and flickrShowDescription="FALSE" to no avail.
I'd try actually changing the titles of these images to remove the word "hidden" (at least temporarily, for testing purposes) to see if this is, indeed, the cause of your problem.
If this does resolve your problem, then maybe you could use a term other than "hidden" (perhaps something like "secret" instead).

I'll try to figure out exactly what is causing this problem (whether it is a Flickr or Juicebox issue) to see if it can be resolved without changing your image titles.
I'll post back here once I've had a chance to investigate further.

Incidentally, I've just created a test Juicebox gallery using local images with the word "hidden" in their titles and captions and the gallery displays all images so, at the moment, it does not look like a Juicebox issue (at least not with local images).

I've also just added the word "hidden" to one of my own Flickr images (in the title and description) and a new Juicebox test gallery displays this image without any problem.

Very strange...
I'd certainly try removing all instances of "hidden" from your own images and, failing that, try reuploading them to Flick (as additional images and/or replacing the current images) to see if this helps.

I'll take another look at this later on when I have more time.
I hope you get on OK in the meantime. Please keep me posted with any updates on your troubleshooting. Thank you.

I understand your concerns (I truly have the same concerns) but, unfortunately, I have no more insight into the future of AIR than you do and, at this moment in time, I genuinely have no news on the future of JuiceboxBuilder.
All I know is that Juicebox itself is still alive and that work has started on the next version (which will likely be a bugfix release).
I really do not know any more than that. I'm sure that the developers are aware of the AIR issues and all we can do, myself included, is hope that JuiceboxBuilder can live on in some form or other beyond the Harman procurement of AIR.
I wish I had more information (good or bad) to give you but I'm as much in the dark as you are just now.

It should be noted that there are alternative ways of creating Juicebox galleries that do not rely on JuiceboxBuilder and AIR. I realise that these methods may not be suitable for all users (and it is certainly a less than ideal scenario) but the Lightroom plugin at least provides Lightroom users with a longer-term solution (with the Pro version of the plugin featuring full control over all Pro configuration options just like JuiceboxBuilder-Pro).

I'm sorry that I do not have any more information at this time but I'll be sure to post back here if I hear anything relevant to this matter.
Thank you for your concern and continued support of Juicebox.

If you were using Juicebox-Lite, then it could have been due to a WP-Juicebox upgrade.
WP-Juicebox comes bundled with Juicebox-Lite and if you upgrade WP-Juicebox, your Pro 'jbcore' folder will be overwritten with the Lite version.
Reinstating your Pro files is a simple task of uploading your Pro 'jbcore' folder (from your Juicebox-Pro zip file) to your 'wp-juicebox' directory (which should take less than a minute of your time). (You could also just remove the Lite 'jbcore' folder from the WP-Juicebox package before upgrading to prevent your Pro 'jbcore' folder from being overwritten.)

The screenshot of your gallery does seem to conform to the screenshot of your gallery settings window. (The screenshot of your gallery windows shows maxThumbRows="1" and maxThumbColumns="6" and this is displayed in the screenshot of your gallery.)

Setting maxThumbRows="6" and maxThumbColumns="1" will definitely make a difference.

If it does not seem to make a difference for yourself, then the problem is almost certainly a caching issue.
After making changes on an 'Edit Gallery' page, make sure that you click the 'Save' button at the bottom of the page and if you do not see the changes you expect to see, make sure that you are 100% certain that you have completely cleared your browser's cache before reloading your gallery's web page. (Sometimes refreshing the page with F5 or even Ctrl+F5 is not enough.)

I've just double-checked all this by creating a sample gallery in WP-Juicebox v1.5.1.2 (using Juicebox-Pro v1.5.1) using maxThumbRows="6", maxThumbColumns="1" and thumbsPosition="LEFT". The gallery displayed as expected. I then edited the gallery (on the 'Manage Galleries' page and swapped the '1' and the '6'. Again, the gallery displayed as expected (with the rows and columns swapped).

If clearing your browser's cache does not help, then maybe the issue is with server-side caching. Your web host could perhaps have server-side caching enabled on your hosting account and, even though files have changed, your web server could still be serving older versions of these files for a certain period of time.
Please check in with your web host and ask if they have server-side caching enabled on your hosting account and, if so, ask if they would be willing to remove it.
Caching can certainly be useful but it can also sometimes be a hindrance to development.

If you click on the attachment link, the image will be displayed. Below the image, you'll see a download link. Each time the image is downloaded via this link, the download counter is incremented by one. (Most people will be content with viewing the image in place and will not download it.)

WP-Juicebox has individual interface controls for Lite options only.
Pro options must be entered in the 'Pro Options' text area of the gallery settings window, one per line, such as:

expandInNewPage="TRUE"
showImageOverlay="ALWAYS"

This has always been the case with WP-Juicebox (and setting Pro Options in a WP-Juicebox gallery is noted in the WP-Juicebox support page here).

You will find the 'Pro Options' text area in the gallery settings window when you first create a gallery.
You can access the gallery settings window for a pre-existing gallery by going to 'WP-Juicebox -> Manage Galleries' (from the WordPress Dashboard side menu) and clicking 'Edit' next to the gallery that you'd like to modify.

Try adding something like the following to a gallery's 'Pro Options' text area, changing the values as necessary:

thumbWidth="75"
thumbHeight="75"
thumbsPosition="LEFT"
maxThumbRows="10"
maxThumbColumbs="3"

The text in the top-left is the gallery title. To remove the gallery title, set  the following in the gallery's 'Pro Options' text area:

galleryTitlePosition="NONE"

The text near the bottom of the image is the caption area.
By default, WP-Juicebox uses the image filename (without the extension) as the image title. ("b-forgiving-1" in your screenshot.)
You can remove this by deselecting the 'Display Image Titles' checkbox (just above the 'Pro Options' text area).
You can remove the image number ("6/6" in your screenshot) by setting the following in the 'Pro Options' text area:

showImageNumber="FALSE"

You can remove the entire caption area (without needing to remove the image title and image number separately) by setting the following in the 'Pro Options' text area:

captionPosition="NONE"

For reference, a list of all Pro Options can be found here.

I hope this helps.

The 'Home' icon is the Back Button, displayed when backButtonPosition is set to either TOP or OVERLAY (and backButtonUseIcon is set to TRUE).

You can have the Back Button redirect to any web page you like by setting backButtonUrl (in JuiceboxBuilder-Pro's 'Customize -> Back Button' section).
The value for backButtonURL can be a relative path (relative to the web page containing the gallery's embedding code) or an absolute path (starting with either http:// or https://), for example:

backButtonUrl="http://www.example.com/index.html"

For reference, a list of all Back Button options can be found here.

I hope this helps.

Yes, I agree. It would be better to get to grips with WordPress 5 and new Gutenberg Editor as this seems to be the way forward and WordPress are not going to drop the Gutenberg Editor any time soon.

Your screenshot shows that WP-Juicebox is installed and active and that you've managed to add a Juicebox gallery to your post.
All you need to do now is attach images to your post (using core WordPress functionality) and Juicebox will automatically display them in the gallery.

(1) Click the 'Add Block' button (the '+' in a circle near top-left in your screenshot) to add a new Gutenberg block to your page or post.
(2) Select a 'Gallery' block. (You'll find it in the 'Media' section.)
(3) Click the 'Media Library' button within the 'Gallery' block.
(4) Drag and drop the images that you want to attach to your page or post (i.e. the images that you would like to be displayed in your WP-Juicebox gallery) from your hard drive into the media window.
(5) Wait until the images have finished uploading.
(6) Reorder the images (if necessary) by going to the 'Create Gallery -> Media Library' section (within the media window), selecting 'Uploaded to this post' from the drop-down menu and then dragging and dropping the thumbnails into the order you require.
(7) Close the media window via the cross at the top right. (Do not click the 'Create a new gallery' as this will create a native WordPress gallery in addition to your WP-Juicebox gallery.)
(8) You can now safely remove the 'Gallery' block from the post. (Using a 'Gallery' block is just a convenient method of attaching images to a post.)

WordPress does not make it easy to attach images to a post (or to see images which are attached to a post) but the above method works.

If you find you still have trouble attaching images to a post, then there are a couple of alternatives.

(1) You could use a Flickr account as the source of images for your Juicebox gallery. WordPress would then have no part in the image management of your gallery.

(2) You could choose not to use WP-Juicebox at all and, instead, create a Juicebox gallery on your computer (with JuiceboxBuilder) and manually embed the gallery into your WordPress post using the baseUrl method documented here. Here is an example of how you could do this:

Step #1
Create your gallery with JuiceboxBuilder and save it to a new empty folder named "my_gallery_folder".

Step#2
Upload the entire gallery folder (not just the contents) to the root directory of your web server (using an FTP program such as Filezilla).

Step #3
Create a new 'Custom HTML' Gutenberg block (in the 'Formatting' section) and paste the following embedding code (changing the gallery dimensions and background color if you like):

<!--START JUICEBOX EMBED-->
<script src="/my_gallery_folder/jbcore/juicebox.js"></script>
<script>
    new juicebox({
        baseUrl: "/my_gallery_folder/",
        containerId: "juicebox-container",
        galleryWidth: "100%",
        galleryHeight: "600",
        backgroundColor: "#222222"
    });
</script>
<div id="juicebox-container"></div>
<!--END JUICEBOX EMBED-->

The leading slashes in the paths above denote your root directory so the code above will work without modification as long as your gallery folder is named "my_gallery_folder" and has been uploaded to your root directory.

Incidentally, you can upload your gallery folder to anywhere on your web server as long as the two paths within the baseUrl embedding code (the path to the 'juicebox.js' file and the baseUrl entry itself, pointing towards the gallery folder) are correct.

You'll only see the 'WP-Juicebox -> Manage Galleries' link (shown in my screenshot in a post above) on your WordPress dashboard page (not on an 'edit a post' page such as the one shown in your most recent screenshot).
Just click the 'W' icon (the one in the circle at the top-left of your screenshot) to see the WordPress dashboard menu ath teh left of your screen. The WP-Juicebox link will be near the bottom of the list. (This will not help you to attach images to a post, though... it will only give you access to the 'Manage Galleries' page where you can edit galleries (to change configuration options) or delete galleries.)

That's down to the way WordPress works. The only way I've found to see the images attached to a post (whilst creating or editing a post) is to create a 'Gallery' block, check the images in the media window (accessed via the 'Gallery' block') and then remove the 'Gallery' block afterwards.
Otherwise, you can see which images are attached to which posts in the 'Media -> Library' itself (accessed via the WordPress dashboard).

I hope my notes above help somewhat.

This seems like a Drupal-specific gallery structure type of issue (i.e. a problem building the gallery within Drupal rather than a problem with Juicebox itself).

I'm not sure if you are using the Juicebox Module for Drupal but it sounds like you might be.
I don't know you are building your Juicebox gallery or how you'd get the paths of the images from your Lightbox Gallery into your Juicebox gallery's 'config.xml' file.

As the Juicebox Module for Drupal is an unofficial plugin which was not written by ourselves, I would recommend that you post your query in the Drupal forum where the author of the module (Ryan Jacobs) should hopefully be able to help you further.
He is active and very helpful in the Drupal forum and has a much better knowledge that I have of both the module and Drupal.

An alternative to using the module would be to create a gallery first on your computer using JuiceboxBuilder-Lite and then embed the gallery into your Drupal page using the baseUrl method of embedding following the Embedding in a Drupal Site instructions.
In doing so, you would be able to keep each gallery in its own self-contained folder (helping to keep things organized on your web server).

Here's an example of how to embed a gallery (created with JuiceboxBuilder-Liteon your computer) manually into a Drupal page.

Step #1
Create your gallery with JuiceboxBuilder-Lite and save it to a new empty folder named "my_gallery_folder".

Step#2
Upload the entire gallery folder (not just the contents) to the root directory of your web server (using an FTP program such as Filezilla).

Step #3
Create a new Article, select 'Full HTML' from the 'Text Format' drop-down menu and paste the following embedding code (changing the gallery dimensions and background color if you like):

<!--START JUICEBOX EMBED-->
<script src="/my_gallery_folder/jbcore/juicebox.js"></script>
<script>
    new juicebox({
        baseUrl: "/my_gallery_folder/",
        containerId: "juicebox-container",
        galleryWidth: "100%",
        galleryHeight: "600",
        backgroundColor: "#222222"
    });
</script>
<div id="juicebox-container"></div>
<!--END JUICEBOX EMBED-->

The leading slashes in the paths above denote your root directory so the code above will work without modification as long as your gallery folder is named "my_gallery_folder" and has been uploaded to your root directory.

Incidentally, you can upload your gallery folder to anywhere on your web server as long as the two paths within the embedding code (the path to the 'juicebox.js' file and the baseUrl entry itself, pointing towards the gallery folder) are correct.

I hope this helps (or at least points you in the right direction).

Yes, no problem.
A Juicebox gallery has very few server requirements. Please see here for details.

That is correct. Juicebox does not require or use a database at all.