Hi,
Please see the detail Log for the error.In there you will see the Message class and the associated message number.When you get this you just have to check where it is used
(Click on "Where-Used List") it will take you to respective connections and then check the Z program in which it is used and there you can apply a debugger and see which condition fails to pop the error message.
There might be a condition that is failed.So there it can be corrected.
Thanks,
Shamal