This bug is related to IDEA-31626, which I thought was related close enough that the fix there would fix this, but it didn't -- IDEA is marking xs:any content as red when it doesn't need to. The right-click->validate validates successfully, and the XML is loaded properly in the applications, which also validates against the schema as well using Xerces. I believe it also passes XMLSpy's tests.

The actual files I am working with are a lot more complicated than this, but the following example reproduces the problem.

{code:xml|title=anyBug.xsd}
<?xml version="1.0" encoding="UTF-8"?>
<xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema" elementFormDefault="qualified" attributeFormDefault="unqualified">
<xs:element name="root">
<xs:complexType>
<xs:sequence>
<xs:any namespace="##any" processContents="lax" minOccurs="0" maxOccurs="unbounded"/>
</xs:sequence>
</xs:complexType>
</xs:element>
</xs:schema>

{code:xml|title=anybug.xml}
<?xml version="1.0" encoding="UTF-8"?>
<root xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="anyBug.xsd">
	<aValidTag>

	</aValidTag>
</root>

Environment: IDEA 5.1.1 Windows XP bundled JRE 1.5

Issue was resolved