How to handle LabVIEW Error 3: Could not load front panel

[instrumento]

I'm on 2009 SP1 (9.01) which is newer than the 2009 f3 patch (9.0f3).

[Jon_S.]

Hello instrumento,

I don't believe there is a way you can solve this yourself.  You should open a support request with one of our Applications Engineers.  Explain to them that you have SP1 and give them the VI that will not open.  There is no need to send the entire hierarchy.

We have been able to recover these VIs in the past but there is no guarantee.  Sending this VI in will be the best option.

[instrumento]

Sent the VI in already.  Solving it myself would really only be useful if I ran into a lot of these, as, even if NI can fix it, the turn around time is a bit too long.  And while we're converting all our code from 7.1 to 2009 I do need to keep versions of the VI for both 7.1. and 2009....

[instrumento]

Dead end ... 

All NI can suggest is to open the VI with intermediate versions, saving the whole thing, and going up from 7.1. to 2009 step by step.

My code uses the Vision Dev Module, which, as opposed to different versions of LV, cannot be installed on the same machine and I can't afford the time to create virtual machines to accomplish it, so whenever I open the code going up the chain the VI is always broken with respect to all vision types and sub-VIs.

Anyway the code opens and can be saved away as a new hierarchy with 7.1, 8.0, 8.2 but NOT 9.01.  I'm stuck with recreating the VI after wasting a lot of time...

[James@Home]

Did you try to copy all [CTRL+A] the code from the block diagram and pasting [CTRL+V] into a new/blank VI?

I've had this work on correcting wierd LV errors & problems in years past, but not this specific LV9 issue.

Just a thought in case it might save you the time of a complete rewrite?

[instrumento]

Forgot about trick, which I used once to get rid of some insane object!  Didn't work, same problem.

Went back and deleted all Vision related stuff from the VI.  Saved the now severely broken VI.  Opened it in 2009 and it worked! Added the Vision calls and I'm on my way after wasting about two days on such a simple thing.

My suspicion is that 9.01 (2009SP1) fixes this problem for most VIs, but somehow the Vision Development Module also needs to be patche, if it hasn't already

[Kenneth]

This comment is to document a deployment issue that was discovered with the same error code 3.

I migrated a LV 851 project to 901.  On the target PC, a LV851 application (run-time engine) has been running for over a year.  The goal is to deploy an updated EXE based on a LV901 application builder.

To start the migration, I opened my top tree VI with the entire hierarchy in LV 901 ADE.  I build the new EXE and copy it to the target, same folder as the LV 851 EXE.  Setting up the 901 Run-time engine, I thought that I would only need to copy and run the new EXE.  However, the target gives this error code, 3, for the VI, "NI_AALPro.lvlib:LinearFit.vi" 

The cause of this error was a supporting DLL file, lvanlys.dll.  The lv901 EXE copied to a folder with the lv851 DLL's gives this error code. 

Using a clean copy of the EXE and all supporting files (dll's) ran fine on the target.

So a DLL versioning issue might also cause this error code 3.