Hello,
Are you using the FRDM-KW38? Where you able to flash an BLE example before?
Your KW38 might be in Low Power mode. Could you try to do a mass-erase? By using an "unlock kinetis" command in J-Link Commander, or a mass erase command through MCUXpresso, which works as well.
And the Low-Power mode can be disabled by setting the following macro (in the app_preinclude.h header file) to a 0, like so:
/* Enable/Disable PowerDown functionality in PwrLib */
#define cPWR_UsePowerDownMode 0
Hope this helps.
Regards,
Ricardo