When expecting a gallery, do you just see the shortcode on the frontend like this?
Then your shortcode does not get processed. The reasons behind that could be:
JIG is disabled. Check JIG on the plugin list of the WordPress Dashboard, it should be active, not only installed.
Shortcode processing is disabled for the content area you are [...]
In case at least one of these happened:
You received a red "Your jQuery version is old" notice.
This message appeared: "The Justified Image Grid JS is not loaded".
The captions are not showing.
The lightbox is not working.
There is no animation on mouse over.
The gallery doesn't appear.
Then maybe your site uses an old jQuery version or [...]
This problem occurs because in Internet Explorer 6 to 9 all style tags after the first 31 style tags are not applied. It includes inline CSS and loaded .css files. The solution is to decrease the amount of .css files the site loads:
If you use W3 Total Cache, enable its CSS minify feature, to automatically [...]
In case you are completely missing a JIG instance, it is often because the scripts are not loaded on the page. JIG inserts all of its scripts, both inline and .js files into the footer. But your theme might not support this if it doesn't use best practices.
With an FTP client, navigate to your theme's [...]