I have a bare board with the MK02FN64. I am using Segger J-Link and MCUXpresso. I can erase, program and read the MCU flash using Segger's J-Link applications.This implies the device and connections are correct.
MCUXpresso's debugger fails to program the flash & results in a Break at address that is outside the program code (not surprising since the flash was never programmed). The GUI Flash Tool also fails to erase or program the flash.
The Console information indicates that the J-Link is connecting to the device. I do notice that when using the Segger J-Link app, I get a message that the Protection bytes in flash at addr. 0x400-0x40F indicate that readout protection is set (don't know how to disable this in MCUXPresso ?? Using the GUI Flash Tool for Resurrecting locked Kinetis devices doesn't have any effect). Within Segger's app, I can unsecure the device & program it. I can can then read the content & verify it. MCUXpresso does nothing to the flash.