Opera mobile is the most famous browser used in android after dolphin. Dolphin is much capable than opera in displaying flash contents, and playing embedded flash videos.
The most common error message in Opera is host look up for site failed. This error is basically caused because of Opera Turbo. As per Opera’s claim “When Opera Turbo is enabled, webpages are compressed via Opera’s servers so that they use much less data than the originals. This means that there is less to download, so you can see your webpages more quickly.”
But for some relatively new websites Opera turbo fails to fetch the page. So simply disabling the turbo feature will get rid of this error.