Unfortunately, due to certain browser security restrictions, it is not possible to preview Juicebox galleries locally (from your computer's hard drive) in all browsers.
When trying to preview a Juicebox gallery locally in Chrome or Opera, you will see the "Juicebox can not display locally in this browser." message. Please see this FAQ for details:
When I view my gallery locally, I see the message "Juicebox can not display locally in this browser". Why?
However, you can preview Juicebox galleries locally in Firefox (after performing the tweak noted in this forum post), Safari (after performing the tweak noted in this forum post) and Edge (no tweak required).
Please note that this applies only to previewing a gallery locally. There is no problem once the gallery has been uploaded to a web server where it can be viewed in any modern browser without issue.
I hope this helps to clarify things.