I do not understand why sub-vi notifiers dun work? When I create a program with similar notification without having to create sub-vi notifications, it works.

[astroboy]

When I create a notification system, It can work when I send item, timer and visible controls. But because I decide to add notification system into a bigger application and it is a reusable function. So I create them as sub-vi notification. Before I add into the application, I tested it out. The error reads 1094. Why is this so? I have no clue as I have debugged it.

And is it possible that at any one time, one of the multiple send-notifiers can send msg to only one receive-notifier?

[altenbach]

You get error 1094 because the sendnotify vi is not consistent between the cluster you wire to the "element data type" of "obtain notifier" on the left and the notification cluster you wire to the "send notofication".
While the two clusters look the same, they are different because the elements are ordered differently!

To fix: right-click on the cluster constant all the way to the left. and select "Reorder Controls in cluster...". Now click on each controls in the cluster from top to bottom (first blue, then green, then orange). (Even easier would be: (1) delete the cluster constant on the right, right-click on the notification terminal and select "create constant". Wire the new diagram cluster constant to "obtain notifier".)

Now the coercion dot on
the "send notofication" disappears and error 1094 no longer occurs.

[astroboy]

Never knew that the smallest detail can cause error.
I came to know about reorder cluster in constant.

Thank you very much again for your help.
(Just award you 4 star medals!)
Clement