Error Dashboard for Umbraco
The errors your visitors hit, not the ones your server noticed.
Collects 404s, 500s, TLS and DNS failures from visitors’ browsers using Network Error Logging, shows them on three Settings dashboards, and emails subscribed users when a site’s error volume goes abnormal — judged against the site’s own history rather than a threshold you had to guess. Note that NEL is Chromium-only, so every figure is a lower bound.
dotnet add package Our.Umbraco.ErrorDashboard
Requires Umbraco 18 and .NET 10. On the Umbraco 17 LTS, install the 17.x line instead - the package major follows the Umbraco major:
dotnet add package Our.Umbraco.ErrorDashboard --version "17.*"

Documentation
MIT licensed. Part of a set of three Umbraco 18 packages: Content Dashboard for Umbraco · Error Dashboard for Umbraco (this one) · TrueCopy for Umbraco