I manage to connect to the DVR with my smartphone, but whenever I'm trying to view the recorded files, address the Settings or Live-view, I keep getting an error message: "Camera Initialization failed" (see attached screen capture). I reset the DVR, updated the firmware according to the instructions, reinstalled the mobile app, but I keep getting this error.
I tried a different Android-based smartphone (cheap Chinese one), and everything works fine.
I checked and verified that the app has all the required permissions on my smartphones.
I'm frustrated and I would greatly appreciate to get help with this issue. Thanks.

Try this one
a) turn airplane on
b) turn wifi on
c) turn location on (no need to have a gps lock)
d) connect to K2's wifi network
e) call application