What changed in "discovery"?

Home Assistant 0.107.7

I added a panel_iframe: to my config.yaml, and when I went to CHECK CONFIGURATION, I got an error in another section that had been fine for months:

# Discover some devices automatically ("New Devices Discovered")
    - plex_mediaserver
    - google_cast

The error is:
“Invalid config for [discovery]: value is not allowed @ data[‘discovery’][‘ignore’][0]. Got ‘plex_mediaserver’. (See /config/configuration.yaml, line 42).” [Line 42 is “discovery:”]

So, what changed in “discovery” that I missed?

The discovery as I had it worked for years on my Raspberry Pi installation of Home Assistant, and for the past month on my NUC installation. Frequent check configs and never a problem with Discovery.

Until tonight.

That’s why I was wondering what changed? Why is check config just today giving this error?

Ah, it looks like it was probably part of the plex breaking change in 107: https://www.home-assistant.io/blog/2020/03/18/release-107/#breaking-changes

Yeah, just remove plex_mediaserver from your ignore list. Discovery was removed from the Plex integration as discovery didn’t provide enough info to allow you to use the UI ignore feature. It might come back later when it’s less annoying.