PHP Warning: Invalid argument supplied for foreach()

Hi there,

After updating to the newest version of the plugin, I began seeing these errors in my server log:

[Tue Jan 02 13:31:05.969787 2018] [:error] [pid 13299] [client 186.94.21.71:20055] PHP Warning:  Invalid argument supplied for foreach() in /var/www/html/wp-content/plugins/paid-member-subscriptions/includes/functions-plugin-notifications.php on line 38, referer: https://xxx
[Tue Jan 02 13:31:37.993097 2018] [:error] [pid 13299] [client 218.173.152.13:22997] PHP Warning:  Invalid argument supplied for foreach() in /var/www/html/wp-content/plugins/paid-member-subscriptions/includes/functions-plugin-notifications.php on line 38, referer: https://xxx
[Tue Jan 02 13:31:38.202690 2018] [:error] [pid 13123] [client 218.173.152.13:19351] PHP Warning:  Invalid argument supplied for foreach() in /var/www/html/wp-content/plugins/paid-member-subscriptions/includes/functions-plugin-notifications.php on line 38, referer: https://xxx
[Tue Jan 02 13:31:38.623649 2018] [:error] [pid 13275] [client 218.173.152.13:23283] PHP Warning:  Invalid argument supplied for foreach() in /var/www/html/wp-content/plugins/paid-member-subscriptions/includes/functions-plugin-notifications.php on line 38, referer: https://xxx
[Tue Jan 02 13:31:38.817794 2018] [:error] [pid 13311] [client 218.173.152.13:33569] PHP Warning:  Invalid argument supplied for foreach() in /var/www/html/wp-content/plugins/paid-member-subscriptions/includes/functions-plugin-notifications.php on line 38, referer: https://xxx
[Tue Jan 02 13:34:04.421877 2018] [:error] [pid 13339] [client 197.43.140.39:17251] PHP Warning:  Invalid argument supplied for foreach() in /var/www/html/wp-content/plugins/paid-member-subscriptions/includes/functions-plugin-notifications.php on line 38, referer: https://xxx
[Tue Jan 02 13:35:08.918257 2018] [:error] [pid 13299] [client 119.76.1.202:9045] PHP Warning:  Invalid argument supplied for foreach() in /var/www/html/wp-content/plugins/paid-member-subscriptions/includes/functions-plugin-notifications.php on line 38, referer: https://xxx
[Tue Jan 02 13:35:14.834467 2018] [:error] [pid 13289] [client 119.76.1.202:31051] PHP Warning:  Invalid argument supplied for foreach() in /var/www/html/wp-content/plugins/paid-member-subscriptions/includes/functions-plugin-notifications.php on line 38, referer: https://xxx
[Tue Jan 02 13:35:21.753887 2018] [:error] [pid 13312] [client 119.76.1.202:15115] PHP Warning:  Invalid argument supplied for foreach() in /var/www/html/wp-content/plugins/paid-member-subscriptions/includes/functions-plugin-notifications.php on line 38, referer: https://xxxx
[Tue Jan 02 13:35:23.520058 2018] [:error] [pid 13258] [client 119.76.1.202:17125] PHP Warning:  Invalid argument supplied for foreach() in /var/www/html/wp-content/plugins/paid-member-subscriptions/includes/functions-plugin-notifications.php on line 38, referer: https://xxx

Is this something can be fixed/ looked into?

Thanks,