Kibana 5 loading nothing after upgrade

I just upgraded to ES5 & Kibana 5. ES5 is working and while Kibana is running, when I try to load it, it just gives me a blank page with the sidebar to the left. I know I have data in my database so this is strange.

Nothing is in /var/log/kibana/kibana.stderr. If I look at kibana.stdout though, I notice it's trying send a response where it's getting a 404 error. It's trying to access the url: /elasticsearch/myIndex/_mapping/field/extraStuff...

Does anyone have any ideas or is there additional info I can provide to help?

Provem solved. For those with a similar strange issue, I found a random file in /var/lib/kibana/uuid_old which had one line of garbage. By moving it somewhere else and restarting Kibana, everything came back to normal.

Glad you were able to figure it out, Matt! Thanks for posting your solution.

CJ