Cannot customize Wordpress theme
Website in question: http://believerstrust.org.
I'm accessing the dashboard via believerstrust.org/wp-admin and then trying to customize the theme (in this case, Parallax Pro, a Genesis theme) using Appearance>Customize. The resulting screen is practically dead, though: I can see the options (Site Title & Tagline; Background Images; Header Image; Widgets; etc.) but the preview is just gray and clicking on the options does nothing. I've looked into Wordpress's community support and the best response so far has been "reinstall Wordpress," which seems like a bit of a nuclear option.
I'm accessing the dashboard via believerstrust.org/wp-admin and then trying to customize the theme (in this case, Parallax Pro, a Genesis theme) using Appearance>Customize. The resulting screen is practically dead, though: I can see the options (Site Title & Tagline; Background Images; Header Image; Widgets; etc.) but the preview is just gray and clicking on the options does nothing. I've looked into Wordpress's community support and the best response so far has been "reinstall Wordpress," which seems like a bit of a nuclear option.
While this is likely not the issue as you have probably already done so, be sure that you have installed the Genesis framework as Parallax Pro depends on it.
First, to rule out the theme itself, try activating the Twenty Fifteen theme to see if the customizer works with it. If not, the issue is related to somewhere else in WordPress.
Try disabling any plugins that you have installed as they may be interfering with the customizer.
If the customizer still doesn't work with a different theme, and all plugins disabled, the issue is very likely within WordPress core and may require a clean installation.
Best regards,
JeffMa