In 4.7.1 no Software Version is displayed:
Where back in 4.5.6 it was visible:
I think it might be at line 191 in server-session-details.jsp where .getSoftwareVersion() was changed to .softwareVersion.
<c:choose>
<c:when test="${not empty inSessions and not empty inSessions.toArray()[0].softwareVersion}">
<c:set var="softwareVersion" value="${inSessions.toArray()[0].softwareVersion}"/>
</c:when>
<c:when test="${not empty outSessions and not empty outSessions.toArray()[0].softwareVersion}">
<c:set var="softwareVersion" value="${outSessions.toArray()[0].softwareVersion}"/>
</c:when>
<c:otherwise>
<c:set var="softwareVersion" value=""/>
</c:otherwise>
</c:choose>