Website isn't showing Joomla install

[Admin]

It’s the same issue as this other topic I just replied to. And the solution is also the same (but replace WordPress with Joomla).

My website cannot load template

The page you see is the page that’s actually set up on your website. Looking at your account, I also see a WordPress installation in there, but the original index.php file from WordPress has been replaced with the page you see now. To go back to using your WordPress site, please replace your current index.php with the index.php from a fresh copy of WordPress. Alternatively, you may want to replace all WordPress files in case any other files have been overwritten.

I see this “Our website is coming soon” page a lot, mostly from people who wonder why their actual website is gone, but I have no idea where it’s from. Do you have any idea where this page may have come from?