Error 42 When Building Application When Using LabVIEW

Updated Jul 3, 2026

Reported In

Software

  • LabVIEW
  • LabVIEW Application Builder Module

Issue Details

  • Why am I encountering Error 42 when building an application?
  • After mass compiling, no error shown, but I am still encountering the same issue. Why?

Solution

You will need to go into LabVIEW.ini file and add the configuration setting NewAppBuilderCache.Enabled=False, setting it to false forcing it to use legacy mode application builder. 

File path to find LabVIEW.ini:

  • For 32-bit editions, C:\Program Files (x86)\National Instruments\<LabVIEW version>\
  • For 64-bit editions, it is C:\Program Files\National Instruments\<LabVIEW version>\

Additional Information

It's less likely but also possible that this issue presents as Error 1 instead of Error 42.

In this case, the project would be originally made in an older version of LabVIEW.

Related Links

Where Does LabVIEW Store Configuration Settings?

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