URI is not registered (Settings | Languages & Frameworks | Schemas and DTDs)

& Frameworks | Schemas and DTDs)

This error message typically appears in an Integrated Development Environment (IDE) or text editor that supports XML and related technologies. It means that the Uniform Resource Identifier (URI) that you are trying to use is not recognized or registered in the IDE's settings.

URIs are used to identify resources on the web, such as web pages, files, or APIs. When working with XML, you may need to reference a specific URI to access a schema or document type definition (DTD) that defines the structure and rules for your XML document.

To fix this error, you need to register the URI in your IDE's settings. This involves adding the URI to a list of recognized schemas or DTDs, along with any relevant metadata such as the version, namespace, and location.

The specific steps for registering a URI vary depending on the IDE or editor you are using. However, most tools provide a dialog or configuration file where you can add or edit schema and DTD information. You may also need to download or import the schema or DTD file into your project or workspace.

Once you have registered the URI, you should be able to reference it in your XML documents without seeing the "URI is not registered" error. This will help ensure that your documents are correctly validated and formatted according to the specified rules and standards.