Corrupt VI block diagram (trying to view BD crashes LV)

[K1200LT_rider]

The corrupted version 2010 VI in the attachment is "8810A control.vi."  I've put a couple days' work into it, so it would be nice to get it back.  I can open it fine to view the front panel.  When trying to view the block diagram, an outline of the BD window appears and LV freezes.  Usually, after a short while, LabVIEW itself completely disappears.  No error message; no sign of it in the task bar or anywhere.  I tried saving the VI to a previous version, but LV gets an error.  When trying to "Duplicate hierarchy to new location", I get a popup saying "LabVIEW: Generic file I/O error."  I then made a copy of the VI, opened it, and tried deleting everything from the front panel completely.  Still couldn't switch to the BD.

I think what caused the error was when I accidentally clicked my mouse button as I happened to be moving the cursor quickly across the BD of this VI.  I couldn't tell if it hit or moved something on the BD.  I can't remember for sure, but I think that at that moment LV froze and I had to kill it and restart.  After that happened yesterday, I changed over to working on other VIs that weren't affected.  I'm assuming I'm going to have to recreate it (because I hadn't created any backups yet).    From now on I hope I can remember to back up projects at least twice a day.  I've used Mercurial and it works well.  Hard lesson learned.

[JÞB]

Sounds like you have an "insane object" on the BD.  LabVIEW doesn't like that- but, it does happen infrequently.  In 10+years of wire slinging I've had 3 insane objects show up.  Of course I use a source code repository, enable periodic saving, and my  IT dept does regular backups.  Never lost more than a few hours work.  except for that "First" time.   Pain is a good learning mechanism. 

[Darin.K · Accepted solution]

Try this.  I saved for LV9, opened with LV9 then did a BD cleanup.

[K1200LT_rider]

Darin,

I was able to open your reworked VI and view the BD fine.  I'm very puzzled as to how you could save it to a previous version when I couldn't.  I wonder if I have a problem with my LV installation?  Or, maybe there is a special situation with my code that caused the error.  I'll attempt to save a known good VI to previous versions (and then this VI, again).

Anyway, however you did it, thank you very much... you've saved me a lot of duplicate wire-working.  It's all now saved using my local version control!  Feel free to ask me for any favors in the future.

[Darin.K]

Here is the chain of events, as best I remember.

0. Read post and download zip file.

1. Open only bad file, ignore all subVIs, controls, etc.

2. Save as LV9, simply assumed LV10 would crash.

3. Open VI in LV9, open BD, see, code, "Gee, that was easy"

4. Try to change case structure, crash.

5. Restart LV9. Open VI again.  Open BD, Ctrl-U, now much happiness.

6. Save VI, post final version.

7. Achieve fame and fortune

If I had to guess, not having the SubVIs around probably made a difference.