Unable to display the front panel of the VI

[JackDunaway]

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Ben wrote:

i have to right-click and choose open.

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As for the issue at hand, choosing "Open" from the Context Menu on a project item would yield the message "Unable to display...", just as double-clicking the project item yields the same message.

[Ben]

more shots in the dark...

Darren's recent Nugget on what is kept in the LV data folder mentioned cached stuff. What is there before and after closing and re-opening may tell us something.

If you just wait a short while and retry, same error?

Ben

[JackDunaway]

If "short while" means 3 minutes or less, yes, I've waited at least that long.

[gsussman]

I can confirm now that the problem I am seeing on my systems is the same one that Jack has been seeing.

When attempting to open one of these "stuck" FP vis, from the project I get the same dialog "Unable to display the front panel...blah...blah...blah....It may have been removed"

As for waiting awhile, I have gone at least an hour between getting the FP stuck and a LV restart...it made no difference.

Another thought I had was to delete the vi from the diagram (only called this one time in the hierarchy) and re-add it. No difference and no front panel.

Message Edited by gsussman on 06-03-2010 03:26 PM

[Ben]

I can offer nothing more at this point other than "it sounds like a race condition" inside LV.

Ben

[JackDunaway]

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Ben wrote:

I can offer nothing more at this point other than "it sounds like a race condition" inside LV.

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Exactly the reason I originally posted this problem. This symptom does not really affect me (once a week is not bad, a few times a day like gsussman would get annoying), but that symptom points to a potentially more serious root cause. Then again, the root cause could be benign, just annoying. One way or another, I would like anyone who has seen this behavior to at least post "me too" to get a gage on how widespread the problem (Bug?) might be.

[gsussman]

Another piece of information on this issue.

If you get one of these "Stuck" FP vis, and run the code, putting a breakpoint on the VI, then attempting to step into it, will cause it to execute without opening the front panel and at normal execution speed.

The issue also exists when working under LV RT.

I am still having to completely shut down and restart about 3-4 times per day because of this issue. 3 or 4 times does not seem like much, however when you are attempting to debug a large system (software and hardware) where software startup actions drive specific hardware conditions, it becomes a huge pain in the butt. Restarting LV equates to me having to shut down both the software and hardware, reinitialize, establish my physical plant conditions and pick up where I left off (10-20 minutes cycle time depending on what I am doing).

Do that 4 times and I end up wasting an hour and 20 minutes of my day.......more significant than restarting LV 4 times.....

[charris]

gsussman:

If you go to the SubVI Node Setup (from the context menu), is the problem subVI set to show the front panel when called? Does changing that setting alter the behavior at all?

Would anyone be willing to post a project or VI that this can be reproduced with?  🙂

[gsussman]

Caleb,

The subVI nodes I have had issues with have NOT been set to show front panel when called. Most are either lower level processing VIs or utility functions that would be a real pain for the GUI if they opened every time they got called (taking focus from the GUI)

I have the same issue as Jack with respect to posting the project (large project (several thousand VIs), propriotary info, etc...) The other issue is that the problem is not releated to any specific VI (vis seem to do this randomly from run to run). It sounds more like something related to the code that opens and closes the actual FP windows that something stored in the VI.

[Tanya_V]

Hi Jack and gsussman,

Have either of you tried mass compiling vi.lib as was previously mentioned in the thread?

Also, do either of you get any errors when reopening LabVIEW after this front panel error occurs?

Take care!