New 2026 Q1 Feature: .NET (Core) 8.0 Improvements

[Christina_R]

.NET (Core) 8.0 Improvements

When developing VIs that use .NET (Core) 8.0 in LabVIEW 2026 Q1, you now have the ability to create probes on wires that are .NET (Core) 8.0 references, with similar functionality to the probe for .NET Framework references.

In addition, LabVIEW 2026 Q1 now uses arrays of references to pass data to/from .NET (Core) 8.0 assemblies that operate on arrays. If you wrote VIs in previous versions of LabVIEW, these were treated as references, and you will have to update your VIs to work in LabVIEW 2026 Q1.

[pawhan11]

Did some tests -  calling .NET core code that returns array of structs. 

It will crash LabVIEW without any warning or error.

Attached reproducer.

[Christina_R]

Thank you for testing and reporting this issue! I've filed Bug 3458951 to track it.

[jyoung8711]

So, I went to test out some of the .NET Core functionality.  Specifically I went to see if (a) the memory leak was fixed (from this thread: https://forums.ni.com/t5/LabVIEW/State-of-Net-Core-in-2025Q3-Bugs-and-Errors/m-p/4454466)

And to check if any of the various issues mentioned here have been resolved: https://forums.ni.com/t5/LabVIEW/State-of-Net-Core-in-2025Q3-Bugs-and-Errors/m-p/4454466

Unfortunately, I got no further than installing LabVIEW 2026 BETA, registering, and starting it up than I go this lovely error when accessing the build in Guid library:

To reproduce, I dropped down the Constructor node, selected the "Select .NET Core Constructor", browsed to System.Private.CoreLib --> System --> Guid.  Then I dropped down an invoke node, and clicked the "method".  That's when I got this pop-up.

After clicking "OK" the method list DID pop-up... so, it's pretty unclear what the issue is actually suggesting.  The VI did run (correctly) when I started it.  But an error pop-up still seem undesirable.

I'll work through some of the other use-case/testing that I've been doing on the .NET Core stuff shortly.

[jyoung8711]

Ok, so I ran through some of my outstanding issue tests...

1. Property / Method Browser : Works again! This is great 🙂

2. Memory Leak : (described here ) : This is still an issue.  I reproduced it using my Guid example above in a For loop.  Consistent with that post, I see about a 4 KB RAM increase per loop iteration -- despite closing the references (behavior doesn't change if I put the initial reference in shift registers).

3. Error 1782/1781s Which appear to be related to default inputs? (described here )  -- This is still a problem.  Whenever this error occurs it seems to just completely crash the .NET Core engine (you can actually see that in the above screenshot.  I re-opened that VI after one of these crashes, and you can see that the nodes are all black, and the VI would no longer run).

I continue to be excited about the availability of .NET Core in LabVIEW -- It opens up a HUGE range of open source tools/APIs to LabVIEW -- and the upcoming (hopefully) cross-compatibility with Linux... But thus far, it's proved to be mostly unusable for me and my team (despite this now being the 3rd version where it's been supported) 😞

[soundslikesound]

Hello Christina, question little bit off topick. Is newer .NET 9 and .NET 10 supported in Labview 2026 Q1?