1-Do you get any error message before crash or labview just disappears without anything?
2-If the arrow is broken, can you choose "File>>Save with options" and save everything to llb. Open your top level from llb, fix the broken arrow and then do save. Have you tried that?
Essentially i am trying to have LabVIEW resaved everything into brand new file rather than saving things into existing file.
A Rafiq