Troubleshooting/FAQ   
8.1 Firmware update via WBM or CLI not possible 
  SCALANCE W780/W740 to IEEE 802.11n Web Based Management 
432  Configuration Manual, 08/2018, C79000-G8976-C267-13 
The firmware is transferred to the device.  
 
note that the transfer of the firmware can take several minutes. During the 
transmission, the red error LED (F) flashes.
 
Once the firmware has been transferred completely to the device, the device is restarted 
automatically.