Hi Beth Altshuler,
I also use the SDK2.5 version, you can check my first reply:
SDK_2.5.0_FRDM-K66F\boards\frdmk66f\bootloader_examples\freedom_bootloader
But, just as I have told you, I didn't relocated to flash address 0XA000, I am using the IAR project, you can check my first reply picture, I relocate the app address to 0XC000, because I find after build, the bootloader size already larger than 0XA000, but small than 0xc000, that's why I suggest you also relocated to 0XC000, and try my generated files.
Please test my generated code first, I also use the SDK2.5, then same as you, my generated code works OK on my frdm-k66 board with KinetisFlashTool.
After you try my generated code, tell me the test result.
You said you are using KDS, but in the SDK generated tool, the toolchian IDE don't have the KDS version, how you generate it? Maybe you need to use the MCUXrpesso IDE instead of the KDS:

If your FRDM-K66 board on board debugger is using the JLINK firmware, you can use the JLINK commander to do the mass erase at first, then just follow my way to test my generated code, after make your board works, then we can check more details:
1. Change the opensda firmware to JLINK firmware, please check this link:
www.nxp.com/opensda
2. use JLINK commander(find in the JLINK driver) to do the mass erase: unlock kinetis

3. Send my file:freedom_bootloader.hex to the FRDM-K66FJ

4, Then open the kinetis flash tool, also use my led_demo_freedom_c000.bin

After updated it, wait about 5 seconds, the led will blink.
Have a great day,
Kerry
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