LABVIEW CLOSES WHEN OPENING BLOCK DIAGRAM

[mprantl]

I noticed a strange behavior of LabView 2016. When I build an add-on package with VIPM that contains a library that is protected with NILM (NI license manager) I have the following problem.

If I install that package (on a different computer; again using VIPM) everything works fine and also the example program runs fine and Labview is (correctly) telling me that the add-on is running in evaluation mode.

However, if I now try to open the block diagram of a VI that is part of the library that was licensed with NILM then Labview silently closes (no error message, nothing; it just disappears and everything I worked on is lost). If I open the block diagram of a VI that is not part of the library protected by NILM (like the example VI or one of its sub-Vis) then everything works fine.

This happens with Labview 2016 but not with Labview 2019.

Now the strange thing happens: Once I license my add-on using NI License Manager (that is, the add-on is no longer in evaluation mode) then I can normally open the block diagram and everything works fine.

Is this behavior known? Is there a work-around?

This bug is very annoying to someone who is downloading an add-on and evaluating it, when suddenly Labview closes and all of the work is lost.

[RavensFan]

That is strange.  I have not heard of that happening before.

You didn't state which add-on this is.  What is it, and is this an NI add-on or something from a third part?

[mprantl]

It is an add-on that I wrote myself. However, it does not depend on the content of the VI. It seems like it only depends whether the VI is from a library with a license attached to it or not. Furthermore, as soon as the license is not in evaluation mode anymore, everything works fine. 

[mprantl]

I did a bit more investigations.

1. I created a project with two VIs. They are exactly the same. One is a copy of the other. They are called insideLib.vi and outsideLib.vi.

2. One of these VIs is inside of a library (called myLib.lib), the other is outside (as the names indicate). 

3. I attached a license to myLib.lib with the NI License Manager Utility (using LabView 2019 as this is not available for LabView 2016).

4. I then saved the project for a previous version (LabView 2016)

5. and created a VIPM package from the 2016 version (using VIPM 2019). 

6. When I install that package (using VIPM 2019) on a different or the same computer (doesn't matter) I have the behavior that as soon as I try to open the block diagram of insideLib.vi with LabView 2016, LabView closes without any error message. If I try to open outsideLib.vi everything works. (btw, both VIs (inside and outside the lib) are not broken and can be run)

7. If I now activate the package (so it is no longer in evaluation mode) I can also open the block diagram of insideLib.vi. 

8. If I remove the license files (.lc and .xml) altogether from my machine (so essentially having no valid license) then insideLib.vi is shown as broken and cannot be run (saying there is no license), BUT, when I now try to open the block diagram LabView does NOT close but opens a dialog stating that the block diagram cannot be opened because the library requires activation. This behavior is fine. 

Hopefully, this sheds some light on what is going on. 

Thanks, Manfred