Midi Control Center - Firmware update fail on Mac OSX
During the firmware update of one of your products, the following error may be encountered:

Failed to open the device."
To get rid of this error message, please follow the steps below:
- Close the MIDI control Center
- Unplug concerned device or unplug the USB HUB if the device is connected to the USB HUB.
- Open Spotlight (top right corner of your screen)
- Type : “Audio MIDI setup”
- Open the Audio MIDI setup utility
- In the menu bar, select - “Window” then “Show MIDI window” or “Show MIDI Studio” on 10.10
- The MIDI Studio should now show up will all the MIDI devices already installed on your MAC.
- Select the concerned device and click the "Remove Device" button (At this moment, the device may be identified as a generic device.)
Example: Here with Beatstep Pro

=> Once deleted, if you try again, the update process should work as intended.
Et Voila...