The download of the specified resource has failed.
recently, "the download of the specified resource has failed." error boring me a lot.

the ssl cert on the web server had a hostname mismatch error. this caused the problem with using xmlhttp.send() resulting in "the download of the specified resource has failed.".


the solution is:
change
xmlhttpclass sender = new xmlhttpclass();
to
serverxmlhttp sender = new serverxmlhttp();

then when executing sender.send(request);, everything is back to normal.