Showing results for 
Search instead for 
Did you mean: 

NAN in preamble makes labwindows crash

Go to solution

Hi all,


I am using Labwindows CVI 2015 (v 15.0.0) and I faced a problem where the symptoms where:

  • Autocompletion features not working
  • Labwindows CVI would not respond when trying to close the IDE

This was happening with only one of my project.  After investigation this was happening because  I was initializing some global variables (before main function) using NAN constant or NotANumber function.

Once I replaced NaNs by a finite value and initialized the global variables in the main or in any other functions both previously mentioned symptoms disapeared.


I have no idea if this is an expected behaviour but I though it would worth share the information as I found nothing else about these symptoms on Internet.


I Hope that will help others.

0 Kudos
Message 1 of 4



after your report I have tried this scenario and I observed the same - closing CVI results in a 'not responding' message....


To add some more data: I used existing code of mine and just changed one line, the initialization of a double from 0.0 to NAN; then I compiled and ran the code without problem (this variable was not used in this run). I quit my software, returning to the IDE and then tried to exit CVI - when asked I discarded the changes, all open tabs disappeared, and the above mentioned message appeared...

0 Kudos
Message 2 of 4
Accepted by Rémy.Lassalle-Balier



This is another aspect of this bug.

Although it's another case, the cause is the same. We are planning to fix this in an upcoming release.

The workaround for this case is to do the initialization in a function(e.g at the beginning of main()) instead of global scope.



0 Kudos
Message 3 of 4

Hello Constantin,


Thank you for your feedback! It is good to read that it is going to be fixed Smiley Happy Despite the 'stability release 2015' there are still soo many known issues...

0 Kudos
Message 4 of 4