"Mark as Read" button causes an error on the page

[m-weeks]

When I use the "Mark as Read" button it gives me the following error:

Warning: Invalid argument supplied for foreach() in /wp-content/plugins/bbpress-pencil-unread/bbppu-forum-marks.php on line 297

After some investigation, I noticed the meta value added to my user was the number 1 with a bunch of whitespace characters before it for bbppu_marked_forums.

I am using bbpress 2.6.5 and wordpress 5.4.1