Electronic Brake System Unavailable Warning Light
 

I just bought 2015 Jeep Trailhawk to flat tow. Towed it home (3 hour drive) after getting Blue Ox tow rig installed. Worked well. I got home and tried to do the shift out of neutral procedure but won't work. The first step to do this is to "apply parking brake" but i get yellow P! warning "Park Brake Temporarily Unavailable" so I am stuck. No idea what to do looked at many forums and cannot find any help. Thanks for any suggestions.