FHIR validation with Schematron in Android

Question

I am trying to create a simple android application which will be used to validate FHIR resources. I am trying to use and implement the code provided by hapi fhir found below using Schema/Schematron Validator:

https://hapifhir.io/hapi-fhir/docs/validation/schema_validator.html

The issue here is that I am trying to run the exact same code given in the example end I get an IllegalArgumentException.

My code is this:

public class MainActivity extends AppCompatActivity {

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    Patient p = new Patient();
    p.addName().setFamily("Smith").addGiven("John").addGiven("Q");
    p.addIdentifier().setSystem("urn:foo:identifiers").setValue("12345");
    p.addTelecom().setSystem(ContactPoint.ContactPointSystem.PHONE).setValue("416 123-4567");

    validateResource(p);
}

private void validateResource(Patient patient) {

    FhirContext ctx = FhirContext.forR4();

    FhirValidator val = ctx.newValidator();

    IValidatorModule module1 = new SchemaBaseValidator(ctx);
    IValidatorModule module2 = new SchematronBaseValidator(ctx);
    val.registerValidatorModule(module1);
    val.registerValidatorModule(module2);

    ValidationResult result = val.validateWithResult(patient);
    if (result.isSuccessful()) {

        System.out.println("Validation passed");

    } else {
        // We failed validation!
        System.out.println("Validation failed");
    }
}

}

Which is the same code as used in the example. However I get the following error.

E/AndroidRuntime: FATAL EXCEPTION: main Process: fhirvalidation, PID: 2365 java.lang.RuntimeException: Unable to start activity ComponentInfo{fhirvalidation/fhirvalidation.MainActivity}: java.lang.IllegalArgumentException: http://www.w3.org/2001/XMLSchema at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:3449) at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:3601) at android.app.ActivityThread.handleRelaunchActivityInner(ActivityThread.java:5456) at android.app.ActivityThread.handleRelaunchActivity(ActivityThread.java:5362) at android.app.servertransaction.ActivityRelaunchItem.execute(ActivityRelaunchItem.java:69) at android.app.servertransaction.TransactionExecutor.executeCallbacks(TransactionExecutor.java:135) at android.app.servertransaction.TransactionExecutor.execute(TransactionExecutor.java:95) at android.app.ClientTransactionHandler.executeTransaction(ClientTransactionHandler.java:58) at android.app.ActivityThread.handleRelaunchActivityLocally(ActivityThread.java:5415) at android.app.ActivityThread.access$3300(ActivityThread.java:237) at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2076) at android.os.Handler.dispatchMessage(Handler.java:106) at android.os.Looper.loop(Looper.java:223) at android.app.ActivityThread.main(ActivityThread.java:7656) at java.lang.reflect.Method.invoke(Native Method) at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:592) at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:947) Caused by: java.lang.IllegalArgumentException: http://www.w3.org/2001/XMLSchema at javax.xml.validation.SchemaFactory.newInstance(SchemaFactory.java:192) at ca.uhn.fhir.validation.SchemaBaseValidator.loadSchema(SchemaBaseValidator.java:125) at ca.uhn.fhir.validation.SchemaBaseValidator.doValidate(SchemaBaseValidator.java:76) at ca.uhn.fhir.validation.SchemaBaseValidator.validateResource(SchemaBaseValidator.java:168) at ca.uhn.fhir.validation.FhirValidator.validateWithResult(FhirValidator.java:219) at ca.uhn.fhir.validation.FhirValidator.validateWithResult(FhirValidator.java:186) at fhirvalidation.MainActivity.validateResource(MainActivity.java:48) at fhirvalidation.MainActivity.onCreate(MainActivity.java:32) at android.app.Activity.performCreate(Activity.java:8000) at android.app.Activity.performCreate(Activity.java:7984) at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1309) at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:3422) at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:3601)  at android.app.ActivityThread.handleRelaunchActivityInner(ActivityThread.java:5456)  at android.app.ActivityThread.handleRelaunchActivity(ActivityThread.java:5362)  at android.app.servertransaction.ActivityRelaunchItem.execute(ActivityRelaunchItem.java:69)  at android.app.servertransaction.TransactionExecutor.executeCallbacks(TransactionExecutor.java:135)  at android.app.servertransaction.TransactionExecutor.execute(TransactionExecutor.java:95)  at android.app.ClientTransactionHandler.executeTransaction(ClientTransactionHandler.java:58)  at android.app.ActivityThread.handleRelaunchActivityLocally(ActivityThread.java:5415)  at android.app.ActivityThread.access$3300(ActivityThread.java:237)  at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2076)  at android.os.Handler.dispatchMessage(Handler.java:106)  at android.os.Looper.loop(Looper.java:223)  at android.app.ActivityThread.main(ActivityThread.java:7656)  at java.lang.reflect.Method.invoke(Native Method)  at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:592)  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:947)  I/Process: Sending signal. PID: 2365 SIG: 9

Is there something obvious I am missing? Because I can't figure something out. Any hint would be useful, thank you!!