Hi, downloaded latest version and tried it on a local copy of our joomla site before upgrading live.
I do not see comments on articles any more, instead i see this error message in the log files:

[Fri Oct 19 11:50:28.793890 2018] [php7:notice] [pid 8908:tid 1940] [client ::1:53407] PHP Notice:  Undefined index: sv-SE in C:\\xampp7\\htdocs\\v201810\\components\\com_comment\\helpers\\utils.php on line 252

[Fri Oct 19 11:50:28.793890 2018] [php7:notice] [pid 8908:tid 1940] [client ::1:53407] PHP Notice:  Trying to get property 'sef' of non-object in C:\\xampp7\\htdocs\\v201810\\components\\com_comment\\helpers\\utils.php on line 252

And when looking into the component it refers to setting of language:

		$languageCode = $languages[ $lang->getTag() ]->sef;

Is there some configuration I have missed (or am I using a too high PHP version?)

Our production CComment version is 5.3.5
/Staffan