One of 'ref' or 'name' must be present in a local attribute declaration

[ariza84]

Exception in thread "main" ly.stealth.xmlavro.ConverterException: ::::48:86:4565:src-attribute.3.1: One of 'ref' or 'name' must be present in a local attribute declaration.
at ly.stealth.xmlavro.SchemaBuilder$ErrorHandler.throwExceptionIfHasError(SchemaBuilder.java:445)
at ly.stealth.xmlavro.SchemaBuilder.createSchema(SchemaBuilder.java:111)
at ly.stealth.xmlavro.SchemaBuilder.createSchema(SchemaBuilder.java:95)
at ly.stealth.xmlavro.SchemaBuilder.createSchema(SchemaBuilder.java:80)
at ly.stealth.xmlavro.Converter.main(Converter.java:171)
Caused by: ::::48:86:4565:src-attribute.3.1: One of 'ref' or 'name' must be present in a local attribute declaration.
at org.apache.xerces.impl.XMLErrorReporter.reportError(Unknown Source)
at org.apache.xerces.impl.xs.traversers.XSDHandler.reportSchemaError(Unknown Source)
at org.apache.xerces.impl.xs.traversers.XSDHandler.reportSchemaError(Unknown Source)
at org.apache.xerces.impl.xs.traversers.XSDAbstractTraverser.reportSchemaError(Unknown Source)
at org.apache.xerces.impl.xs.traversers.XSDAttributeTraverser.traverseNamedAttr(Unknown Source)
at org.apache.xerces.impl.xs.traversers.XSDAttributeTraverser.traverseLocal(Unknown Source)
at org.apache.xerces.impl.xs.traversers.XSDAbstractTraverser.traverseAttrsAndAttrGrps(Unknown Source)
at org.apache.xerces.impl.xs.traversers.XSDComplexTypeTraverser.processComplexContent(Unknown Source)
at org.apache.xerces.impl.xs.traversers.XSDComplexTypeTraverser.traverseComplexTypeDecl(Unknown Source)
at org.apache.xerces.impl.xs.traversers.XSDComplexTypeTraverser.traverseLocal(Unknown Source)
at org.apache.xerces.impl.xs.traversers.XSDElementTraverser.traverseNamedElement(Unknown Source)
at org.apache.xerces.impl.xs.traversers.XSDElementTraverser.traverseLocal(Unknown Source)
at org.apache.xerces.impl.xs.traversers.XSDHandler.traverseLocalElements(Unknown Source)
at org.apache.xerces.impl.xs.traversers.XSDHandler.parseSchema(Unknown Source)
at org.apache.xerces.impl.xs.XMLSchemaLoader.loadSchema(Unknown Source)
at org.apache.xerces.impl.xs.XMLSchemaLoader.loadGrammar(Unknown Source)
at org.apache.xerces.impl.xs.XMLSchemaLoader.load(Unknown Source)
at ly.stealth.xmlavro.SchemaBuilder.createSchema(SchemaBuilder.java:109)
... 3 more

Please, Can you help?