There is no app configured at that hostname.
Perhaps the app owner has renamed it, or you mistyped the URL
The site was down even few months back and they started having issues with the price. Sometimes it was below the market price and sometimes higher and hence I shifted to Google price indicator due to the inconsistencies. It will be back soon but I hope they correct those price errors.
Price errors have nothing to do with them as the math is pretty simple (x + y + z ) / 3 . they simply get the average from different exchanges.
Error Itself come from Localbitcoins , they are the ones who have few bugs with the price and since Preev.com connects to their API ... well It gets bugged. (but you can fixed it by unchecking Localbitcoins from preev settings)