Plesk 11.x / Windows :: Site Has Disappeared Though Still Shows Normal In Parallels Panel

Site has disappeared, though still shows normal in Parallels Panel

I keep a simple site for my art portfolio and some misc files hosted with unlimitedwebhosting.co.uk and Parallels Plesk.

Yesterday I noticed that the site and all its contents give a 404 error, and the home page shows the default page generated by Parallels Plesk Panel. However, all my files are still accessible from ftp and the Panel:

The index.html file is still the same old one as it should be, yet the homepage doesn't show it.

As per the default setup, all the content of the website is in the httpdocs folder, not the root. Though I did try copying the index.html to the root and see if that worked, but it did not. I'm very inexperienced when it comes to web hosting and everything related, so I'm not sure if it's somehow user error or if I should try to contact Parallels.

Here's a history of emails I received from them - notice how the invoices are followed by multiple payment confirmations:

So perhaps cancelling the one payment made them think I wanted to cancel the hosting and the site was taken offline? I don't know.