I upgraded from Kirby v1 to v2 locally and everything went ok.
I deployed to my server, and after logging in to the panel I only see a blank page. I enabled debug mode, and it looks like this is the root cause:
Fatal error: Uncaught exception 'Exception' with message 'Invalid route' in /var/www/panel/app/panel.php:203
Stack trace:
#0 /var/www/panel/index.php(47): Panel->launch()
#1 {main}
thrown in /var/www/panel/app/panel.php on line 203
It was working fine with Kirby v1. I have already tried updating to all the latest packages (it is Ubuntu).