what does this error mean ?

[maria vincent]

Error: *** Project 'ble_app_beacon_s110_pca10028', Target 'nrf51422_xxac_s110', Device 'Nordic Semiconductor::nRF51422_xxAC' is not supported by Toolchain ! ***.

[Hung Bui]

Hi Maria, 

Please let us know which SDK you are using ? Which IDE you are using (KEIL/IAR/ECLIPSE) ?
If you are using KEIL5 please make sure you use .uvprojx project file.