Successful web request, web server functioning fine, application functioning fine, but the application needs to tell the user they have done something wrong in-app.

In my world for example there's a piece of third party hardware I need to take a bunch of data from and deliver it to the user. One part of that data is telling the user there's an error and they need to perform an IRL interaction with it to fix something, but the rest of the data and images in the payload are good