can't build uart sample project

[[email protected]]

Hi, I am using nRF52840-DK; Window 10; Embedded Studio and try to run sample project:C:\Nordic_Semi\nRF5_SDK_15.0.0_a53641a\examples\peripheral\uart\pca10056\blank\ses

Compiling error

Could anyone tell me what I did wrong? 

[awneil]

A good first step is always to put the error message into the 'Search' box.

Whence: devzone.nordicsemi.com/.../133776