What it means
The ESPHome dashboard looks the device up by its mDNS name (name.local) and gets no answer, so it cannot upload over the air or read logs.
Why it happens
- The device is not on Wi-Fi: wrong SSID or password in secrets, 5 GHz-only network (ESP chips need 2.4 GHz), too far from the access point.
- mDNS does not cross networks: the device is in an IoT VLAN or guest Wi-Fi, and ESPHome is in another.
- ESPHome runs in Docker without host networking.
How to fix it
- Look at the device’s own log over USB: it prints Wi-Fi errors. If it opened its fallback hotspot, connect to it and enter the network.
- Give the device a fixed address in the router and add wifi: use_address: 192.168.1.50 to the config, or turn on mDNS repeating between VLANs.
- For Docker run ESPHome with network_mode: host.
Useful tools
/esphome-config-generator/ · MikroTik config generator