Fatal Internal Error: "support.cpp", Line 1726

[DuncanW]

I have a colleague who has built a LabVIEW 7.1 project and gets an error dialog when starting it up...

Fatal Internal Error : "support.cpp", line 1726

LabVIEW version 7.1

You will lose any unsaved work. For assistance in resolving this problem, please relaunch LabVIEW, or

contact National Instruments.

The LabVIEW project is basically a user interface to a CPP DLL and contains very little except the DLL & a whole bunch of controls & indicators.

Does anyone have any clues as to what might be causing it as he can't seem to be getting past this point.

Cheers

Duncan

[Tony_G]

Hi Duncan,

Do you know what the CPP.DLL is being asked to do by the LabVIEW VI?  Had the program been working fine before the error occured?

Best regards,

Tony

[DuncanW]

The CPP DLL is an automated test written in C++ & compiled as a DLL. The LabVIEW app in this case is providing the user interface, so sets up frequencies levels etc to be used for the test & when the 'Go' button is pressed, the DLL sets up the instrument, performs the test & returns the result to the LabVIEW code, which displays it to the user in an indicator.

I know it could be better written completely in LabVIEW but it came from a legacy C++ test code, which didn't have any user interface & it was felt easier to add a LV UI rather than making it a C++ EXE with a visual front end.

The app has been working fine, then a tweak done to the C++ code & recompiled.

[Tony_G]

Hi Duncan,

Do you know what the tweak was?  Everything worked up until this point, so are you able to roll it back to be sure you can get back to a working application?

Best regards,

Tony

[Rob Stedman]

Hello,

I am a colleague of Duncans and I'm currently woring on this problem.

Your suggestion of rolling back the code seems sensible but has problems.

The code update that caused the labview fatal internal error was not really a tweak - it was a complete update for a third party library (in C/C++) to drive a satellite demod chip.

It would seems likely that this updated code in the DLL is causing, however it seems that labview traps the error and reports the problem being in "support.cpp line 1726". This gives no visibility as to what might be the cause of the error. 

I have tried visiting the "fatal error support page" http://www.ni.com/support/failure/ but this drew a blank.

I have also tried adding some debug to the C/C++ DLL code and suspect the problem is related to sending I2C messages via an COM port connected to an RS232 to I2C converter device. 

None  of this really helps as I can't see what may be wrong with the code I suspect is causing the problem and I cannot roll it back. The previous version of the 3rd party library makes lots of successfull I2C read/writes so I am confused .

Can you help explain what the labview error message means (it must have a fairly precise meaning ?)  I can't find any information on the meaning behind this message.  

Thanks for any help you can offer,

Rob