I did it. MHRAFootnote had a different code under the "Handle the different types of input documents." section, I copied it from the working styles and now everything is ok.
This was the different / missing code to change:
This was the different / missing code to change:
<xsl:choose>
<!-- Gets the name of the style as it will be displayed in Word 2007 / 2010. -->
<xsl:when test="b:StyleName">
<xsl:value-of select="msxsl:node-set($data)/general/stylename"/>
</xsl:when>
<!-- Gets the version information for the style in Word 2007 / 2010. -->
<xsl:when test="b:Version">
<xsl:value-of select="msxsl:node-set($data)/general/version"/>
</xsl:when>
<!-- Sets a version number in Word 2013. -->
<xsl:when test="b:XslVersion">
<xsl:choose>
<xsl:when test="msxsl:node-set($data)/general/version2013">
<xsl:value-of select="msxsl:node-set($data)/general/version2013"/>
</xsl:when>
<xsl:otherwise>
<!-- Fallback method : use a dummy version number of 1. -->
<xsl:text>1</xsl:text>
</xsl:otherwise>
</xsl:choose>
</xsl:when>
<!-- Set the name of the style in Word 2013. -->
<xsl:when test="b:StyleNameLocalized">
<xsl:value-of select="msxsl:node-set($data)/general/stylename"/>
</xsl:when>