An important Smart Flow & Cubex troubleshooting step is checking if the Smart Flow password matches and corresponds with the Cubex password. 

All you need to do is to open your Settings -> Dispensing Machine (at the bottom of the list) and take a look at the password as shown on the screenshot below:

You may also wish to view THIS document for further information re Cubex file number errors.

If further assistance is required, please submit a Support ticket.