Labview: Null Window ... stopped at unknown on the block diagram

Hi,
I have a fairly large program that was written in Labview 6.0. Recently we upgraded to Labview 9.0 and this program was exported to an executable with the new version.
When running the executable I sometimes get the following error as seemingly random places. I have not been able to make it crash when not using the executable. Labview: Null Window. The top-level VI ".vi" stopped at unknown on the block diagram of ".vi"
I apologise for having to blank out the vi names but i cannot give vi names, say what the software is used for or give over code. I can say that it uses NI USB 6212 IO cards, interfaces with Rhode and Swartz instruments and uses alot of file IO.
I was hoping that someone could give me a hint on how to debug such an error. I have noticed that When this error occurs, the memory use almost doubles.
Thankyou
James 
Solved!
Go to Solution.

I think you open the front panel of a VI that has it's front panel removed during the build. Try to adjust the built settings of that specific VI to include the front panel.
Ton
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    Solved!
    Go to Solution.

    Thanks, but that isn't at all what I am trying to do. I want to
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    global variables make robots angry
    Attachments:
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