Error 1055 when creating tree control

[ni_n_hp_fan]

I'm programmatically adding elements to a tree control in LabVIEW 7.1.1. As far as I can tell, I can sometimes add items to my list and sometimes not. For instance, at times the following works: if I have a parent level called "Grandparents A", I can add a child level called "Parents", and a child level to that called "Children". I can then add a new parent level, "Grandparents B", with the same children levels, "Parents" and "Children" with no problem:

Grandparents A
-Parents
--Children
Grandparents B
-Parents
--Children

Then for some reason I attempt to add another parent level, "Grandparents C", and attempt to add "Parents" and/or "Children", and I get error 1055 "LabVIEW: Object reference is invalid."

This error could be linked to the secondary beta software that I am using, but was just curious is anyone has ever seen anything like this.

Any ideas?

[DavidT]

Im not sure what the error could be but have you created your own vi to do this? There is an example, 'Family Tree.vi' that is shipped with LV and does exactly what you are trying to do. Perhaps you can look at this example to find out where you might be generating your error or modify it to suit.
Hope this helps.

Message Edited by DavidT on 06-21-2005 12:49 PM

[ni_n_hp_fan]

Thanks. It actually turned out that I had overlooked the small fact that I was destroying the reference to my tree control. Funny how that could cause a problem.