Fix Zeroconf Port Error After Home Assistant Upgrade
Hey Guys, Facing a Zeroconf Setup Error After a Home Assistant Upgrade? You're Not Alone!
Alright, fellow smart home enthusiasts, let's talk about something that can really throw a wrench into your perfectly automated world: Home Assistant Zeroconf setup errors right after a core upgrade. Many of you, just like the original user, might have recently updated your Home Assistant Core to version 2025.12.0 (or a similar recent version) from an older build, only to find some of your essential integrations, like Apple TV and Thread, mysteriously refusing to load. It's super frustrating, right? One minute everything's humming along, the next your smart devices are acting like they've never met each other. This often points to a deeper issue, and in this specific case, the logs are screaming about zeroconf and a peculiar "Invalid URL: port can't be converted to integer" error. If you've seen this message, especially originating from homeassistant.setup, you've hit the exact problem we're going to tackle today. It's a real head-scratcher when core components fail to initialize, and it impacts everything that relies on them for discovery and communication. You might have already tried some basic troubleshooting, like checking your default_config: or scouring community forums for similar experiences, feeling like you're going in circles. The zeroconf component is absolutely vital for Home Assistant, as it handles the automatic discovery of services and devices on your local network. Without it, integrations that depend on this discovery mechanism, such as those for Apple TV, many media players, and even some Thread network components, simply won't be able to find or connect to their respective devices. This means your smart home ecosystem could be effectively crippled, leaving you scratching your head and wondering what went wrong with an update that should have brought improvements, not headaches. The sudden loss of functionality can be a real bummer, particularly when you're relying on these devices for daily routines or entertainment. So, let's roll up our sleeves and figure out what's causing this hiccup and get your Home Assistant back to its prime.
Decoding the Error Logs: Why "8123" Isn't a Valid Port
When Home Assistant starts throwing errors, the log details are our best friends, even if they sometimes look like a jumble of tech-speak. In this scenario, the traceback gives us some very specific clues that pinpoint the problem directly to your URL configuration. The core of the issue lies in this cryptic message: ValueError: invalid literal for int() with base 10: '8123\' and ValueError: Invalid URL: port can't be converted to integer. What's happening here, guys, is that Home Assistant uses a Python library called yarl (Yet Another URL library) to parse and validate the URLs you provide in your configuration. This library is super strict, and for a good reason – URLs need to be precise. When yarl tries to extract the port number from your configured external_url or internal_url, it expects a clean, unambiguous integer. However, in our problematic example, the URL was something like https://XXXX.duckdns.org:8123\. See that trailing backslash right after the port number 8123? That little character, innocent as it may seem, is the entire source of our woes. Python's int() function, which yarl uses to convert the port string ('8123\') into an actual number, simply can't make sense of it. It expects digits only, and that backslash is not a digit. Consequently, the conversion fails, it raises a ValueError, and the whole zeroconf setup process grinds to a halt. This cascading failure is why your Apple TV and Thread integrations can't load – zeroconf is essentially the foundational service that tells Home Assistant what's available on your network, and if it can't even get its own URL straight, it certainly can't advertise anything else. It’s a classic case of a tiny syntax error causing a massive breakdown in functionality, demonstrating just how critical proper configuration is, especially when dealing with network-sensitive components like zeroconf. Understanding this precise error message is the first step to a quick and effective fix, transforming a confusing bug into a clear, actionable problem.
Pinpointing the Problem in Your configuration.yaml: The Rogue Backslash
Okay, so we've identified the culprit as that pesky trailing backslash within your URL, but where exactly is it hiding in your Home Assistant setup? Most often, this issue stems from the homeassistant: section of your primary configuration.yaml file. Specifically, we're talking about the external_url and internal_url parameters. These are crucial settings that tell Home Assistant how it can be accessed from outside and inside your network, respectively. For many users, especially those using dynamic DNS services like DuckDNS, these URLs are vital for remote access and for various integrations to function correctly. Let's look at the example provided in the problem description: you probably have something similar to this in your configuration.yaml:
homeassistant:
external_url: https://XXXX.duckdns.org:8123\
internal_url: https://XXXX.duckdns.org:8123\
packages: !include_dir_named packages
Do you see it now? Right there, at the end of both external_url and internal_url, is that single backslash \. While it might seem harmless, or even perhaps you intended it for some other purpose (like escaping a character, which isn't necessary or correct here), in the context of a URL, it's totally out of place and causes the yarl library to choke when trying to parse the port. It's like trying to tell someone a phone number is