.NET Framework apps still in production

Updated 1 October 2026 · BugsRadar team

The ASP.NET MVC app from 2014 still earns money. The Windows service next to it still moves files every night. Nobody wants to touch them, which is exactly why their errors go to an Event Log nobody opens. Adding BugsRadar is a package reference and a few lines of configuration, not a migration.

It runs where you are

The packages target .NET Standard 2.0, which .NET Framework 4.6.1 and later can reference (Microsoft recommends 4.7.2 or later for .NET Standard 2.0 libraries). The dependencies are floors, not the latest versions: Microsoft.Extensions.Http 8.0, Microsoft.Extensions.Logging.Abstractions 8.0 and Newtonsoft.Json 13.0.4, all of which run on .NET Framework. See Install.

No dependency injection needed

An old app has no host builder, and it doesn't need one. Create a BugsRadarClient once with the key and keep it for the life of the process, as in Console apps and scripts; call SendException from wherever you catch. In ASP.NET, that place is Application_Error in Global.asax; in a Windows service, the catch around the work loop. Reports leave through a background queue, so the request or the loop never waits for the network.

The logger you already have

Most apps of that generation log with log4net or NLog, and the configuration is already in an XML file. Add the log4net appender or the NLog target there, with the key from an environment variable, and everything logged at ERROR and above arrives in the chat without a line of code changing. Both packages bring BugsRadar with them.

What arrives

The exception type and message, the stack trace, the machine name and the version of the entry assembly, in the chat within seconds, and repeats counted in the same message. A null reference that has been happening in a WebForms page for two years becomes one message with a count on the first day. See What you receive.

What stays out

WinForms and WPF apps you ship to users: the API key is secret and anyone can take it out of a desktop app. BugsRadar is for code that runs on your servers. See Keep the API key secret.

Where to go next

The package reference and the first call are in BugsRadar for .NET. If the app already logs to Seq, Already on Seq needs no package at all.