If the pro is flashing red, please try the following by order:
1. Remove the current set of batteries and put in a NEW set. The unit will then beep and flash. Then connect to the Pro with the app. Schedule a test with the app (there is no need to wait for the test to be over). The light should blink green after. If it does not, continue to step 2;
2. Close your connection with the app:
iOS devices: To close the app running, double-click on the Home button (round button) and then swipe up.
Android: Tap and hold on the app and swipe it to the right.
Once the app is closed;
Press the round button located on the front of the unit. Press and hold firmly for 3 seconds. Once it is done beeping, connect the Pro with the app. Schedule a test with the app (there is no need to wait for the test to be over). If it does not, continue to step 3;
3. Open the Windows CRA SW v4.5*, then plug the cable to the PRO:
Once connected, the unit should give you the error message. If no error message is available (e.g. error 518) or none of the above has worked, please contact us at with the unit serial.
* You must have version v4.5. If you do not, uninstall your current version and reinstall the newest v4.5 by clicking here.