I am new to SQC, and I am hoping to learn how to use it and compare its output with other schema validators. However, I have run into a strange problem. In my attempt to use the QualityChecker class to validate a schema (which I am guessing is the right course of action), I receive the following stack trace:

-------------------------
java.lang.IncompatibleClassChangeError
at com.ibm.sketch.schemaparser.XSDParserImpl.getASModel(Unknown Source)
at com.ibm.sketch.schemaparser.XSDParserImpl.<init>(Unknown Source)
at com.ibm.sketch.schemaparser.XSDParserImpl.<init>(Unknown Source)
at com.ibm.xml.ecm.schema.impl.OpenCloseManagerImpl.initParsers(Unknown Source)
at com.ibm.xml.ecm.schema.impl.OpenCloseManagerImpl.<init>(Unknown Source)
at com.ibm.xml.ecm.schema.impl.OpenCloseManagerImpl.getInstance(Unknown Source)
at com.ibm.xml.ecm.schema.impl.ReferenceImpl.<clinit>(Unknown Source)
at java.lang.Class.forName0(Native Method)
at java.lang.Class.forName(Class.java:140)
at com.ibm.mof.mof13.extn.impl.MofClassExtnImpl.getJavaClass(MofClassExtnImpl.java:142)
at com.ibm.mof.mof13.extn.impl.MofClassExtnImpl.refCreateInstance(MofClassExtnImpl.java:294)
at com.ibm.mof.mof13.extn.impl.FactoryExtnImpl.refCreateInstance(FactoryExtnImpl.java:41)
at com.ibm.xml.ecm.schema.impl.FactoryImpl.refCreateInstance(Unknown Source)
at com.ibm.xmi.xmi11temp.impl.XMIDocumentImpl.newInstance(XMIDocumentImpl.java:399)
at com.ibm.xmi.xmi11temp.impl.XMIDocumentImpl.newInstance(XMIDocumentImpl.java:390)
at com.ibm.xml.ecm.schema.gen.impl.FactoryImplGen.createDatatypeRef(Unknown Source)
at com.ibm.xml.ecm.schema.impl.FactoryImpl.createDatatypeRef(Unknown Source)
at com.ibm.xml.ecm.schema.impl.BuiltInDatatypeDefImpl.makeReference(Unknown Source)
at com.ibm.xml.ecm.schema.impl.TopComponentImpl.makeReference(Unknown Source)
at com.ibm.xml.ecm.schema.impl.BuiltInDatatypeFactory.createAndRegisterGeneratedType(Unknown Source)
at com.ibm.xml.ecm.schema.impl.BuiltInDatatypeFactory.createAndRegisterGeneratedType(Unknown Source)
at com.ibm.xml.ecm.schema.impl.BuiltInDatatypeFactory.<init>(Unknown Source)
at com.ibm.xml.ecm.schema.impl.BuiltInDatatypeFactory.getInstance(Unknown Source)
at com.ibm.xml.ecm.schema.impl.FactoryImpl.instance(Unknown Source)
at com.ibm.sketch.utilities.Lint.findErrors(Unknown Source)
at com.ibm.sketch.utilities.Lint.findErrors(Unknown Source)
at com.ibm.sketch.utilities.QualityChecker.findErrors(Unknown Source)
at com.ibm.sketch.utilities.QualityChecker.findErrors(Unknown Source)
at com.ibm.sketch.utilities.QualityChecker.findErrors(Unknown Source)
at com.ibm.sketch.utilities.QualityChecker.findErrors(Unknown Source)

-------------------------------------
I gather this may have to do with compatibility with Xerces. On my classpath I have Xerces 2.6.0 and SQC 2.2. Having perused the forum, I found similar errors, but they involved much earlier versions of Xerces. Perhaps it is another library entirely causing the problem?

Here is a reasonable representation of code causing the problem:

QualityChecker checker = new QualityChecker();
IError sqcErrors[] = checker.findErrors(schemaLocation);
//schemaLocation is a String

While I am at it, let me also ask this: is this line of code the best way to validate that a schema is well-formed and meets the W3C spec? (Instance validation against a schema is not an issue for me right now...).

Any insight or guidance into the questions I have posed here is greatly appreciated.

Thank you all very much.