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1172 constructor node intermittent problem

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Hi, I am working with some assembly (.net) that is using .NET Framework 4.0.

I have the supporting  .dll and my VI in the same directory on the PC. I am trying to go between two different .dll when I am testing my new code but the problem is that it works only sometimes.

I can have everything working one day and when I am trying to build something new suddenly the old VI that was working before is no longer working and throws a 1172 error.

I have both LabView 2013 and 2015 installed, Windows 7.

I also have a config file

<?xml version ="1.0"?>
    <startup useLegacyV2RuntimeActivationPolicy="true">
       <supportedRuntime version="v4.0.30319"/>


that will force the code to use Framework 4.0 in the same directory and under the LABVIEW directory.

What is it that will make my system so unstable?

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Message 1 of 8

Hey Hasse,


The 1172 error in LabVIEW is just a completely generic error you see whenever a .NET assembly throws an exception. So the error is sourced in the .NET. Check out this article on .NET exceptions in LabVIEW:


Definitely worth noting what that page says on error handling, that should give you more information on what exception is occurring. Take a look at that, and you should also consider posting your LabVIEW code here, so if there are issues in the LabVIEW implementation, people will be better able to help.



Applications Engineering

National Instruments

Cassandra Longley
Senior Technical Support Engineer - FlexRIO, High Speed Serial and VRTS
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Message 2 of 8

Unfortunately, I have not been able to solve this.

I have done what's described in the article and still the error comes up. When placing a probe on the output of the constructor node it shows "Not A Refnum
Refnum (in hex): 0x00000000", at a certain time when it was working the reference did have a number.

I think there must be something in the dll that is causing this, I don't change my outside code.

I will try to get another dll.

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Message 3 of 8
Accepted by topic author hasse

Cason, I found the issue now. The Matlab dll's I tried was built with different versions (32bit vs 64bit).

When using a 64bit dll it was a must to use LabView 64bit version and when using 32bit dll use LabView 32bit version.

So I have to use the 32bit dll because I can't use the LabView 64bit (there is an issue when using this together with the Database Connectivity Tools).

By the way, this incompatibility with the Database has been going on for several years, I think that it is time to get this to work for 64bit LabView.

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Message 4 of 8

hi. i am getting the same problem as yours. could you please tell me where to find dll file in system .Actually i am new in this field.

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Message 5 of 8

hi . i am using 32 dll a.d labview too. but still there is issue with this problem. help me

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Message 6 of 8

this is the error and  i am using 32 of DLL and Labview too

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Message 7 of 8

Are you using a Mathlab dll too? I see that the error says the object is already in use, do you try to open it multiple times?

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Message 8 of 8