[Solved] High volume of PHP warnings from class.WpdiscuzCore.php on line 891

Hello! We are observing a high volume of PHP warnings from wpDiscuz on a website that we support. Examples below:

PHP Warning: Undefined array key 38 in /srv/htdocs/wp-content/plugins/wpdiscuz/class.WpdiscuzCore.php on line 891

PHP Warning: Undefined array key 11 in /srv/htdocs/wp-content/plugins/wpdiscuz/class.WpdiscuzCore.php on line 891

PHP Warning: Undefined array key 122 in /srv/htdocs/wp-content/plugins/wpdiscuz/class.WpdiscuzCore.php on line 891

The errors seem to be present on all posts that have comments. The more comments, the more warnings appear in the log. We did try using the Fix DB tables option as recommended in similar threads, to no avail.

We suspect this may be a problem with the way the plugin gets to the last comment on the list:

$commentListArgs["lastCommentIdInList"] = $commentList[$count - 1]->comment_ID;

It's assuming the total `$count` of comments `-1` will provide the ID of the last comment, but if a comment was deleted, the numbers will not match. Let us know if you observe the same.

Related, we noticed that `lastCommentIdInList` is used by the plugin to `setExtraCache()`. While we are not observing any significant performance issues on these pages, we question if performance may be impacted as a result of this.

Thanks, and let me know if we can provide any further details here.