Recovering From A Crash

[Tim_C.]

I recently had a crash of a large project and was a little frustrated to find out that teh recover feature seemed to miss this crash.

Normally crashes seem to go pretty smooth, i.e. when you relaunch LV it seems to know to recover the last file.

This particular crash went as follows.

1.  Coding along, made frequenct saves of the same file name

2.  Ran debug test runs

3.  Got back to coding

4.  Noticed my second processor was now online for over 10 minutes, have seen this before and a reboot normally corrects the situation.

5.  Did a save, seeme dto work fine

6.  Exited LV 8.5

7.  Selected shutdown

8.  Error popped up about not being able to read a memory area, the error had the words labview in it, sorry I do not have the exact message

9.  Restarted widows XP

10.  Open the latest Top Level VI, Came up with a LV error dialog with only the top level vi name in the upper pane and no description in the lower pane.

11. from that point on the VI was corrupt.

Luckily in this situation I had a previous days backup, BUT there was still a lot of code that was lost at this point

Solution to retrieve code from a corrupt file:

Run the VI analyzer

Review the results, AND select go to (or view or something along that line)

In my situation the vi opened, from that point I was able to copy all that days code that would have been lost and place it in a new vi.

Hope this tip helps

-Tim C.

[Ray.R]

Hi Tim,

You were able to recover a corrupt VI using the VI Analyzer?  Wow!  If so, that's a very valuable tip! 🙂

[David_B]

Hi Tim,

Thanks for bringing up this unexpected behavior.  Let me know if this behavior repeats and I'll report the bug to R&D.  If it does repeat, please make note of all error dialogs that you encounter.  Thanks again!

[Tim_C.]

Here is the cause of the crash

The VI execution is set to run when open

A case structure has NO default case

The VI tries to run but the error dialog comes up and just shows the vi name wwith no error definition.

After a couple seconds the LV debug screen of death pops up which only allows debugging or close.

Once I realized what was going on I used VI analyzer to go in and get access to the VI and correct the default case problem.

The VI started working as required after that.

Best Regards

Tim C.

[Darren]

I just ran across this thread (sorry I was a month late to the party).  Instead of using the VI Analyzer to gain access to a diagram in that situation (run when opened), there's an easier way.  Create a blank VI, drop an Add primitive on its diagram (or do anything else that will cause the new VI to become broken).  Then, drop the problem VI as a subVI on this new VI's diagram.  After that, you can double-click the subVI to open it up in edit mode without it running.

Hope this helps future users in this situation,

-D

[Tim_C.]

Thanks 🙂

[Ray.R]

Thanks Darren,

Your suggestion would make a nice nugget.

RayR