Dear Zaheer,
It looks like somebody might not have activated a function module which is causing this problem.
Go to the transaction SE37 and from the menu go to function group and find group. Key in your function group "ZTEST" in your case (last words after SAPL) and then execute. You will now find the function modules in it.
One of reasons might be the function module is not activated. Activate it or ask your ABAP person to investigate and activate it.
Hope this will resolve your problem.
Thanks,
Srini