They changed the name of the "profiler" file you check to determine to use the 1.5 versus 1.6 member variables in your plgJFBCProfilesKunena class
in /plugins/jfbcprofiles/kunena/kunena.php line 28 change
$kunenafile = JPATH_ROOT . DS . 'components' . DS . 'com_kunena' . DS . 'lib' . DS . 'kunena.profiler.1.6.php';
to
$kunenafile = JPATH_ROOT . DS . 'components' . DS . 'com_kunena' . DS . 'lib' . DS . 'kunena.file.class.1.6.php';
Hope this helps.... can I get a subscription extension for finding that