in my application,there are some reports which are fetching from different url.

In emulator fetching data from a url and displaying fine for all reports,
but after installing apk in mobile device all reports are fine except one report is coming error loading null, even url is fine and in url i am getting data, during emulator it was fine too.
but build apk and install in mobile its showing only error loading null.
please can anyone help me why its happening?