Dear Lee,
It is still unclear the IDE you are using, are you using IAR or another tool? Also, you mentioned you used the openSDA successfully before, is that correct? If so, what changes have you done recently that could have caused such issue?
Moreover, you may use the Jlink commander utility from Segger to unlock the kinetis W devices. Please check a similar thread where a solution to this has been discussed. You may try if that works too.
Link: https://community.freescale.com/message/473258
Regards,
AngelC