Randomly get open file dialog even though the file exists

[rharmon@sandia.gov]

I've been using this vi to write error information to a log for months at this file path C:\LabVIEW Working Folder\Tester Software\Config and Log Files\Error Log.txt and as an executable at this file path

C:\LabVIEW Working Folder\Tester Software\data\Error Log.txt 

Now for some unknown reason randomly but usually on the close i get a file dialog box asking which file to write... 

Any idea what I'm missing... what stupid mistake did I make? It just doesn't make sense...

 

[Lipko]

Are you sure there's no race condition of some sort? Calling this VI parallel with another instance of it? Though it would mean that you set it reentrant and I think it would throw file permission errors, but at first glance I don't see other problems.

Another idea is that your wiring is wrong but fooling you: you have a junction of file_handle and error before the case structure, and the close VI is not after the case but parallel (sometimes before).