Returns a common dialog box error string. This string indicates the most recent error to occur during the execution of one of the common dialog box functions
#include <WinAPIDlg.au3>
_WinAPI_CommDlgExtendedError ( )
| Success: | An error string |
| Failure: | An hexa string of the extended error |
Can return general error strings for any of the common dialog box functions.
_WinAPI_GetOpenFileName, _WinAPI_GetSaveFileName
Search CommDlgExtendedError in MSDN Library.