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Broken Run Arrow in a .NET Calling VI Upgraded to LabVIEW 8.5 or Later with Error "Invalid Constructor" or Other Message

Primary Software: LabVIEW Development Systems>>Full Development System
Primary Software Version: 8.5
Primary Software Fixed Version: N/A
Secondary Software: N/A

Problem:
When upgrading my LabVIEW application to LabVIEW 8.5 or later, my VI has a broken run arrow with an error about my .NET assemblies including "Constructor Node: Invalid Constructor", or my .NET property/invoke nodes now have no visible properties or methods.

Solution:
When calling .NET assemblies in LabVIEW, the assembly being called has it and all dependencies loaded in memory when the calling VI is loaded into memory.  There was a specific bug in earlier LabVIEW versions which allowed some assemblies to be loaded without all dependant assemblies.  This bug was fixed in LabVIEW 8.5 which results in some applications which were not broken in earlier versions to be broken after upgrading to 8.5.  It is important to reiterate that broken VIs in LabVIEW 8.5 or newer result from the .NET assembly missing dependencies; the application called in earlier versions may have been missing necessary dependencies without a broken run arrow.

There are several tools available for helping locate missing assemblies; one such tool is .NET Reflector which is available through the link below.

Related Links:
Lutz Roeder's .NET Reflector

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Report Date: 02/11/2008
Last Updated: 02/11/2008
Document ID: 4IABPDHY

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