Good job on the 2.1 update. It broke the entire wordpress site, on first use after the update. I couldn't even uninstall the theme from admin since that was broken too.
Fortunately I was able to track down the problem to 2 lines of code in wp-content/themes/narga/core/library/layouts/custom-header.php at lines 56 and 60.
Both !empty(get_header_image()) calls in the if statement needed to be replaced by first putting the return value of get_header_image into a variable and using that variable instead. The empty function requires a variable.
So. Good job testing that guys. It kinda looks like you didn't.