Are you using a master key? If your using a valet key that may be your problem. Make sure that there are no fault codes in the PCM. If it has a theft code stored, you have to do a keep alive memory reset before you can program keys.

 I am having the same issue with a 2014 Escape & a 2015 Expedition.  I'm using the MaxiDAS DS808, programming is up to date.  With the Escape, I get complete failure, with the Expedition I get "Limited SECURITY ACCESS GRANTED", but I have yet to find what function I can perform on it.  I'm using master keys with both vehicles, no PCM fault codes, no IPC/instrument cluster codes, and I have used the clear codes function just prior to running the 10 minute security scan.  Need to delete "lost" keys from both vehicles and program 1 key.  Any help is appreciated!

Dennis B.