That site appears to do nothing. Perhaps it is made to steal BTC.
I had it "check" addresses that are very old, with BTC that have not cashed out Forked coins. It said nothing was available on it.
Fake site I say.
Or broken.
Probably broken or something, the owner is one of DT member in here and it worked fine in the past.
Ann thread.
Well, you can use another clam checker. But i just know that.