SubVI does not open (error 3 could not open front panel)

[Haverdings]

For the VI I am working in (trail version of Labview 2011), I have created a subVI. At one time I opened this subVI to adjust the connection terminals -which I have done before- and after saving the file and closing it, the subVI remained unadjusted. In fact, I am not able to open the subVI anymore. And when I want to open the file as a VI (e.g. executing the VI in windows), I receive 'load error code 3: could not open front panel.'

I also cannot preform any tasks such as saving the main program for an older version, because this subVI is present in the program.

Nevertheless, the VI still works as a subVI in the mainprogram I've written -in the way it worked before I adjusted the connection terminals.

Is there any way to resolve my problem, without rewriting the whole subVI? The subVI concerning is attached in this post.

Thank in advance,

ps. after closing Labview, it sends an internal warning report. 

[smercurio_fc]

Your subVI has been corrupted. On the last save something went wrong and the front panel went foobar. That's why it is essential to keep backups during development and to use a source code control system that will help you recover from these situations. Depending on your need you could contact NI tech support directly to see if they can repair the VI.

[David. B]

Hello Stag,

My name is David and I am an Applications Engineer at National Instruments UK.

To clarify the problem, when you receive this error are you trying to run the VI as an executable, standalone file in Windows? If this is the case then I think that I know what the problem could be. When using the Application Builder the Front Panels of SubVI's are removed to reduce file size. It is possible to include them so that they may open and the steps to doing so are listed in the attached link:

http://digital.ni.com/public.nsf/allkb/8F68715444302CAB86256DDD0071C140?OpenDocument

This link explains why you are receiving this error and how to overcome it.

I hope that this helps you and do not hesitate to contact me if you require more assistance.

Regards

[Haverdings]

Dear David B,

Thank you for your reply, however a standalone executable is not the case. The VI is build as a normal Labview VI and is subsequently used as a subVI in another (main) VI. Here the (sub)VI works as it supposed to, however, as mentioned before, it is no longer possible to access the (sub)VI because it is somehow/someway corrupted, I guess (as does smercurio_fc ).

Regards,

[ninlmartijn]

Dear Stag,

I'm sorry for the problems you are having with your sub VI. I noticed that this problem could happen in Labview 2009 and that it was resolved with a patch (f3), but since you are using 2011 we need to forward this problem to our R&D department for further investigation. Can you remember what was changed during the last edit from this sub vi? Also did you make some changes to the vi properties? What were the contents from the VI; I see a mean function, any thin further?

I'm sorry to say that we can't provide you with any short term solution, please let me know if I can assist you with rebuilding the sub VI.

Best regards,

[Haverdings]

Dear Martijn,

The change I made was a rearrangement of the terminals for connectorization as a subVI, then the addition/connection of one extra output to the terminal. During this change the subVI was already inserted as a subVI into the mainVI, but in contrast to the previous times I adapted the subVI (successfully), it failed to do anything when I saved and closed the subVI.

The purpose of the subVI was simply to perform data calculations. Or do you mean something else regarding 'contents' ? 

Fortunately, the subVI wasn't very big, so I will have no problem to rewrite the subVI (if my memory does not fail 😉 and then make the adjustments I wanted to make.

Thank you for your response,

[smercurio_fc]

Lesson learned, I guess. I'd recommend you look into backup procedures and source code control systems. It's very easy to set up a subversion system, and it does not require you to use a server.

[ninlmartijn · Accepted solution]

Dear all,

I added this problem to an already existing bug report (what we call a Corrective Action Request); there was one reported with Labview 2010. I added this case to it. The reference of this request is CAR#251753. With this reference you can always request the status of this bug report.

Best regards,

[Michael.Proctor]

Cannot load front panel.

1. LV2011; Mac OS 10.6.8

2. Changed connector pane.  

Case 1  added new connectors by right -click "add new connector"

the re-link to sub vi did not enlable for the enclosing vi

Case 2 Disconnected and reconnected to a different indicator.

In both cases i was able to editr and open just fine UNTIL

I closed all vis and tried to build the application.

I thne got the error from the build app that it coudl not load the front panel.

No ammount of closoing and restartng labview fixed teh problem.

I might try to open in the windows version. In the past this has helped.

Fortunately I have back ups for  these vi

michael

[Haverdings]

To inform: That is the same problem I experienced, which I recently experienced again. It seems like a recurring problem/error in Labview.

I've created a habit of not closing my subVI's untill I am done with the main VI (subsequently knowing for sure that the subVI is OK), this works for me.