|Editing XML Schemas / XML Schema Text Editing Mode|
The same as in editing XML documents, the message of an error obtained by validation of an XML Schema document includes a reference to the W3C specification for XML Schema. An error message contains an Info field that will open the browser on the "XML Schema Part 1:Structures" specification at exactly the point where the error is described thus allowing you to understand the reason for that error.
Figure: Link to Specification for XML Schema Errors
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 Developer window. Otherwise, for large values of the minOccurs and maxOccurs attributes the validator fails with an OutOfMemory error which practically makes Oxygen XML Developer unusable without a restart of the entire application.
If the schema imports only a namespace without specifying the schema location and a catalog is set-up mapping the namespace to a certain location both validation and the schema components outline will correctly identify the imported schema.