No "States" page (Error 404) on VM

I installed Hass.io 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/core.py", line 626, in onetime_listener
    self._hass.async_run_job(listener, event)
  File "/usr/local/lib/python3.7/site-packages/homeassistant/core.py", line 333, in async_run_job
    target(*args)
  File "/usr/local/lib/python3.7/site-packages/homeassistant/components/person/__init__.py", line 342, in person_start_hass
    self.person_updated()
  File "/usr/local/lib/python3.7/site-packages/homeassistant/components/person/__init__.py", line 363, in person_updated
    self._update_state()
  File "/usr/local/lib/python3.7/site-packages/homeassistant/components/person/__init__.py", 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?