Topic: "Config file not found." message whilst viewing a gallery locally

FAQ: When I view my gallery locally, I see the message "Juicebox can not display locally in this browser". Why?

If you receive the "Config file not found." message whilst viewing a gallery locally (from your computer's hard drive rather than from a web server) in Firefox or Safari, then please read on.

Recently, both Firefox and Safari have introduced security restrictions which prevent the loading of local files, resulting in the inability to preview Juicebox galleries from your computer's hard drive.
Because these security restrictions were introduced after the current version of Juicebox was released, Juicebox is unaware of the problem and displays the "Config file not found." message (instead of a more descriptive message).

There are, however, workarounds for the problems in these browsers:

Firefox (68 or later):

  • Enter about:config in your Firefox browser's address bar.

  • Click past the warning via the "I accept the risk!" button.

  • Enter privacy.file_unique_origin in the search bar.

  • Double-click the Preference Name to change the Value from 'true' to 'false'.

Safari (11 or later):

  • Pull down the 'Safari' menu and choose 'Preferences'.

  • Click on the 'Advanced' tab.

  • Check the box next to 'Show Develop menu in menu bar'.

  • Close 'Preferences'. The 'Develop' menu will now be visible between Bookmarks and Window menus.

  • Pull down the 'Develop' menu and choose 'Disable Local File Restrictions'.

Please note that relaxing browser security restrictions should be done at your own risk (but it should be no more of a risk than using the previous versions of the browsers before the security restrictions were introduced).

Incidentally, it is not possible to preview galleries locally in browsers which use the Chromium web engine (Chrome, Edge and Opera). Please use either Firefox or Safari (using the tweak above) to preview galleries locally.

Also, it is important to note that this problem applies only to previewing galleries locally (from your computer's hard drive).
There is no problem once the galleries have been uploaded to a web server where they can be viewed without issue in any modern browser.

An alternative would be to set up a local web server environment on your computer using a program such an MAMP or XAMPP.
This is not as simple as just changing a browser setting but it would allow you to view a gallery locally in any browser you like.