This error comes up if you have not completed the sensor swapping process as a Manager / Admin shown on Soberlive manual pages 23-24.
After changing the Soberlive sensor and switching on the unit, the "Device error, please contact admin" notification will come up. Click on OK to exit.

Then, log in using your Admin / Manager ID and Pin.
Note that your Admin / Manager ID should be your email address and password used to sign in to the Hub on your computer
If you are usually provided with the option to take a test instead of being shown the admin panel, then the ID you've used to log in may not be assigned as the manager for that device / location (i.e. the Soberlive is detecting you as a normal user).
After successfully logging in as an admin, another notice for calibration may appear. Click "OK" to close the notice and load the admin panel.

Click on the Sensor Swap icon on the admin panel
Enter the new sensor's serial number and then tap "Apply Setting" to save.


If you can't seem to move on to the next step even after logging in with your admin email address (i.e. it keeps going back to "Device Error"), check the following:
1) Check that the email address you used to login as admin is assigned correctly as the MANAGER for that location (you need to log in to the Hub on your computer, then go to Locations to check / assign the manager).
2) Check that the Soberlive unit (based on its serial number) is assigned as a device under that same location. 
3) Once done, go back to the Soberlive device and DOUBLE TAP the bottom right corner of the tablet / screen to FORCE SYNC the latest updates from the Hub to the device. Your device will need to be connected to WIFI in order to do this. 
4) Then, log in to the Soberlive device again using your manager login and password. Continue with the steps from the user manual to complete the sensor swap. 
You can refer to the Soberlive user manual for more information on how to set up devices, managers and locations in the Hub: