V4RB: Valentina file open permission

[Guillermo]

Hello

I want to open a open Valentina database as standard file to make a 
backup copy while is already open, my program flush the database and 
ensures that nothing modified it while is making the backup, but I 
don't want close the database because I have open cursors and I don't 
want to recreate it.

This works fine in Mac but in Windows I can't open the file (even in 
read only mode).

  Why I can't read the file in readonly mode in Windows?

I'm using V4RB.

Best regards

      Guillermo