fn:transform specifies that the option xslt-version should be a decimal.  In the test case fn-transform-err-4, a string is supplied.  Under the rules for options (FO31 1.5 Options) the expected result should be XPTY0004 and not FOXT0002.

A similar problems exist in fn-transform-err-5

    <test-case name="fn-transform-err-4">
        <description>Error - the type of the value supplied for the option 'xslt-version' is incorrect</description>
        <created by="Debbie Lockett" on="2015-03-05"/>
        <dependency type="spec" value="XQ31+"/>
        <dependency type="feature" value="fn-transform-XSLT" satisfied="true" />
        <test><![CDATA[
            declare variable $xsl as xs:string :="<xsl:stylesheet xmlns:xsl='http://www.w3.org/1999/XSL/Transform' version='2.0'>
                <xsl:template match='/'>
                    <out>
                        <xsl:value-of select='.' />
                    </out>
                </xsl:template>
            </xsl:stylesheet>";
            transform(map{"stylesheet-text":$xsl, "source-node":parse-xml("<doc>this</doc>"), "xslt-version":"2.0" })
        ]]></test>
        <result>
            <error code="FOXT0002"/>
        </result>
    </test-case>