Edit online

By default, XML Schema files are validated as you type. To change this, open the Preferences dialog box (Options > Preferences), go to Editor > Document Checking, and deselect the Enable automatic validation option.

To validate an XML Schema document manually, select the Validate action from the Validation toolbar drop-down menu or the Document > Validate menu. When Oxygen XML Editor validates an XML Schema file, it expands all the included modules so the entire schema hierarchy is validated. The validation problems are highlighted directly in the editor, making it easy to locate and fix any issues.

Validation of an XML Schema containing a type definition with a @minOccurs or @maxOccurs attribute having a value larger than 256 limits the value to 256 and issues a warning about this restriction in the Message panel at the bottom of the Oxygen XML Editor window. Otherwise, for large values of the @minOccurs and @maxOccurs attributes, the validator fails with an OutOfMemory error that might make Oxygen XML Editor unusable without restarting the entire application.
Important: If the schema imports only a namespace without specifying the schema location and a catalog is set up to map the namespace to a certain location, both validation and the schema components will correctly identify the imported schema.