Map saga continued... My first post here. Thanks to all that have contributed to this. I bought my Blue on White VIP 2015 K900 this past November with 168 miles on it. It had been a training vehicle for KIA. The software was from 2013/2014. The mnsoft update wasn't available for the 2015 until about 4 weeks ago. I assume they pulled it to tweak it due to all of the issues documented here, so I was hopeful when I downloaded it today. Sadly, after the update installation, I had the same problem as others: a frozen display.
Solution: After 30 minutes of ignition on/off and pushing the reset button every way imaginable, I pressed the reset button and killed the ignition during the reset (before it could display the frozen KIA/UVO screen). On the next start the system booted properly.
Hope this helps. Really enjoying my K900!