It's probably connected with the website, it couldn't sync, just like in the screenshot you gave. I thought maybe something is wrong with the internet but I'm in a different country with good internet, so probably it's not anywhere with the connection. Maybe just like mocacinno said, just try the things on his list.

Is there something specific about why you want blockexplorer.com? Maybe the listed sites above are okay unless there's another functionality that other explorers should have?