I have downloaded the source code to use the following functions.
https://github.com/NordicPlayground/nRF52-ADC-examples
The following problem occurred in version 17, and when I compiled version 15.3, I checked the operation normally.
https://devzone.nordicsemi.com/f/nordic-q-a/73074/i-want-to-take-the-adc-input-and-send-it-to-uart
Compilation works normally, but download does not work.

What is the problem?