When troubleshooting, to view more detailed information than shown in the Log panel, use Open log file to open the current log file in a text editor.
If you receive the error Could not connect to debug probe, verify that J-Link software is properly installed on the system.
If the device has been programmed with memory protection, the nRF Connect Bluetooth® Low Energy app cannot program the firmware. To erase the device, download nRF Command Line Tools from Nordic Semiconductor and issue the following command from the command line:
nrfjprog -e -f <nrf51 or nrf52>
In Windows: If you receive the error Could not load nrfjprog DLL, verify that nRF Command Line Tools are installed.
If you receive errors when trying to open the serial port in the nRF Connect Bluetooth Low Energy app on Ubuntu Linux, you may need to grant serial port access permissions to your user. To do this, run the following command:
sudo usermod -a -G dialout <username>