No "States" page (Error 404) on VM

I installed 0.88 as VMDK image in VirtualBox. Everything works great except I get a 404: Not Found when going to the States page (hassio.local:8123/states). I have frontend: in config. All components work fine and Lovelace works as expected. I get this error on startup:

Overwriting component states

And also this (don’t know if it’s related):

Error doing job: Exception in callback <function EventBus.async_listen_once.<locals>.onetime_listener at 0x7f6a8cf00048>
Traceback (most recent call last):
  File "uvloop/cbhandles.pyx", line 64, in uvloop.loop.Handle._run
  File "/usr/local/lib/python3.7/site-packages/homeassistant/", line 626, in onetime_listener
    self._hass.async_run_job(listener, event)
  File "/usr/local/lib/python3.7/site-packages/homeassistant/", line 333, in async_run_job
  File "/usr/local/lib/python3.7/site-packages/homeassistant/components/person/", line 342, in person_start_hass
  File "/usr/local/lib/python3.7/site-packages/homeassistant/components/person/", line 363, in person_updated
  File "/usr/local/lib/python3.7/site-packages/homeassistant/components/person/", line 374, in _update_state
    for entity_id in self._config.get(CONF_DEVICE_TRACKERS, []):
TypeError: 'NoneType' object is not iterable

Any idea what could be wrong?