The solution expandInNewPage="TRUE" would be ok for me, but the gallery did not open in full screen.
This will expand the gallery to fill the browser window rather than the entire screen but because the gallery is expanded on a page of its own, it will not be affected by any custom CSS and should, therefore, display correctly.
Where can I get the older version 1.4.4.2? I have deleted this version on my laptop, perhaps I got it still on my PC.
Unfortunately, older versions of Juicebox-Pro are not available. Download links always point towards the current version.
Your problem is almost certainly due to either HTML errors on your web page or custom CSS which the gallery might be inheriting.
Please try the following:
(1) Make sure that your web page has a valid Doctyle Declaration at the very top of your web page (with nothing, not even any whitespace, above it). Currently, there are a <head> and a <link> tag above your Doctype Declaration (<!DOCTYPE html>). Without a valid Doctype Declaraion in the correct place, browsers will not know what set of standards the code on your web page should conform to and this can cause unpredictable results.
(2) With a valid Doctype Declaration in place, check your web page for any other HTML errors using the W3C Markup Validation Service and fix any errors reported.
(3) Check your web page's CSS for any rules which apply to all instances of certain HTML tags (such as <div>, <img> or <p>) to be sure that your gallery is not inheriting any of your custom CSS. If you find any such generalized CSS rules, target only those elements on your web page which require them using CSS id or class selectors.
(4) Also, I notice that you are embedding your gallery into a container with an id of '1'.
The HTML 4 specifications state that an id should begin with a letter (a-z or A-Z) rather than a digit.
The HTML 5 specifications are more relaxed but as you do not currently have a Doctype Declaration at the very top of your web page (you have a <head> and a <link> tag above it), browsers may not know what set of standards the code on your web page should conform to and using a single digit as an id might be causing a problem. Try embedding your gallery into a container named 'juicebox-container' instead.
Change:
.. and:
... to:
containerId: "juicebox-container",
... and:
<div id="juicebox-container">
The best solution to #4 would be to fix #1 (ensure that the HTML 5 Doctype Declaration is the very first line of code on your web page with nothing above it).