Answer
This error indicates and issue with the clock source referenced in your code. We recommend referencing the appropriate Application Note for Using the DVK-BL65x and Nordic SDK linked below:
- Application Note - Using the DVK-BL652 and Nordic SDK
- Application Note - Using the DVK-BL653 and Nordic SDK
- Application Note - Using the DVK-BL654 and Nordic SDK
As noted in the Application Note, by default the DVK-BL65x uses the on-chip RC oscillator as its clock source, as opposed to Nordic's development kit or dongle which use an external crystal. The difference in oscillator source should therefore be reflected in the SDK as shown Application Note. Alternatively, you can connect an external crystal as per BL65x DVK User Guide