Do I need to run the secure boot sample before running the asset tracker application for the nrf9160dk?If so where do I find the secure boot Cmake files.I can't find them in my samples folder.

[mayur_ch]

[Øyvind]

This is very strange behavior, I am not able to reproduce this and I don't know the reason.

Have you tried compiling using the command line? See this link.

If this does not help, I suggest that you delete your NCS folder and try to clone the NCS repository in a new folder to start from scratch.