HA wont start after upgrade tp 0.98

a bit of a Noob. After upgrading from 0.84 to 0.98 HA will not start. I can access via Putty but no UI . I have some error in the log:

2018-11-27 18:55:02 WARNING (Recorder) [homeassistant.components.recorder.migration] Database requires upgrade. Schema version: None

2018-11-27 18:58:11 ERROR (MainThread) [homeassistant.components.device_tracker] Unable to load /home/homeassistant/.homeassistant/known_devices.yaml: Config file not found: /home/homeassistant/.homeassistant/known_devices.yaml

Any help is greatly appreciated!

That is a really big jump in versions. There have been a bunch of breaking changes in between those two.

My recommendation is to revert back to your previous version. Then take each new version one at a time and go thru all of the breaking changes for each and get that version working. Then move to the next one.

Or if you don’t have a very big system it might just be easier to start from scratch and add everything back in using the newest docs to make sure it works.

You should be able to delete the homeassistant.db. But you will lose your history and I believe logs. Then restart.

That might fix the “warning” but that isn’t what is causing HA to not start. Warnings don’t prevent starting up.

The “error” is with the “known_devices.yaml” file.

Even if they fix that problem too then unless they have a really simple configuration.yaml then they are likely to have other issues as well.

It may be worth a shot but they should be aware that it may not fix everything…