CAST error - "UnicodeError: label too long"

My chromecast audio devices all fail with the same message:

17-03-14 02:43:16 ERROR (MainThread) [homeassistant.components.media_player] Error while setting up platform cast
Traceback (most recent call last):
  File "/srv/hass/hass_venv/lib/python3.4/encodings/idna.py", line 167, in encode
    raise UnicodeError("label too long")
UnicodeError: label too long

I have discovery off and are referencing my cast devices as follows:

media_player:
  - platform: cast
    name: Hallway
    host: !secret cast_hallway_host
    # also tried directly adding the IP address above

I’m also having this problem. Have you had any success?

My issue was that some device on my network was casting using an ipv6 address. In my case, it was this app:

Pychromecast which HA cannot handled an ipv6 address. Once I configured the AirServer app to not cast and then rebooted home assistant, everything was fine.

I have the same issue. Did you just disabled “Google Cast” in AirServer ?