Status code 506 is a less common error code that indicates a server-side configuration issue. It specifically relates to a feature called Content Negotiation.
Content Negotiation is a process where a server offers multiple versions of a resource, like a webpage, and allows the client (like your web browser) to choose the most suitable one. This can be based on factors like the device being used or the user's preferences.
A 506 error occurs when the server picks a variant (version) of the resource that is itself configured to perform content negotiation. This creates a loop and confuses the system. It's essentially like trying to use a remote control to turn on the remote control itself.
In simpler terms, the server is trying to be too clever and accidentally trips itself up.