Additional Information
Error 5 is generated when a LabVIEW File I/O VI is unable to open a reference to an existing file because another process already has an open reference to the file. This can occur if LabVIEW, another application, or your operating system has already opened the file for writing.
Error 5 is not guaranteed to be thrown in the event that a file is already open and should not be relied upon as a method of preventing race conditions or as a method of controlling file access.