What is a null window error message in a programatically opened VI ?

[jpday]

I wrote a simple VI that calls a subvi and has it opened.
If I call it from the development environment - no problems; however, when, I compile the calling vi AND execute it, I get a message that there is a null window and the subvi has stopped.

[Dennis_Knutson]

I think what is happening is that because you set the windows appearance properties in the main VI and not in the subVI itself, the app builder used the default setting for the subVI and removed it's front panel. You can change this in the application builder by going to the VI Settings tab, slect the subVI, and click the Edit Build Settings button. Change the Remove Panel to No and all should be okay. You can also change the subVI's properties itself (VI Properties>Window Appearance>Customize) and not have to change anything in the app builder.

[Feroz]

Hi,
Here's a Knowledgebase that discusses this error.

Null Window Error when Running Application Built with Sub-VI? [link removed; article no longer available]

I hope this helps.

Sincerely,
Feroz
National Instruments