unable to test rules with unification

[milekpl]

The online editor does not offer unification checks at all. If you have a rule for language with standard unification defined in the grammar.xml, for example for Polish:

<rule id="TEST" name="unification test">
    <pattern>
        <unify><feature id="gender"/><feature id="number"/>
        <token skip="-1" postag="(?:subst|ger):.*" postag_regexp="yes"/>
        <marker>
          <token inflected='yes' regexp='yes'>który|jaki</token>
        </marker>
        </unify>
    </pattern>
    <message><suggestion>test</suggestion>?</message>
    <example correction="test">To były rozmowy, <marker>które</marker> nie miały sensu.</example>
</rule>

You get the following error message:

Error: XML validation failed: org.xml.sax.SAXParseException; lineNumber: 15; columnNumber: 20; cvc-id.1: There is no ID/IDREF binding for IDREF 'gender'.