Error in logs

Hello,
I have just checked logs and i saw that i have this error.
Any advice?

[12-Oct-2018 19:58:46 UTC] PHP Warning:  Invalid argument supplied for foreach() in /home/website/public_html/wp-content/plugins/woo-custom-fields-for-variation/plugin.php on line 56
[12-Oct-2018 19:58:46 UTC] PHP Warning:  Invalid argument supplied for foreach() in /home/website/public_html/wp-content/plugins/woo-custom-fields-for-variation/plugin.php on line 56
[12-Oct-2018 20:01:18 UTC] PHP Warning:  Invalid argument supplied for foreach() in /home/website/public_html/wp-content/plugins/woo-custom-fields-for-variation/plugin.php on line 56
[12-Oct-2018 20:01:18 UTC] PHP Warning:  Invalid argument supplied for foreach() in /home/website/public_html/wp-content/plugins/woo-custom-fields-for-variation/plugin.php on line 56
[12-Oct-2018 20:01:38 UTC] PHP Warning:  Invalid argument supplied for foreach() in /home/website/public_html/wp-content/plugins/woo-custom-fields-for-variation/plugin.php on line 56
[12-Oct-2018 20:01:38 UTC] PHP Warning:  Invalid argument supplied for foreach() in /home/website/public_html/wp-content/plugins/woo-custom-fields-for-variation/plugin.php on line 56
[12-Oct-2018 20:02:01 UTC] PHP Warning:  Invalid argument supplied for foreach() in /home/website/public_html/wp-content/plugins/woo-custom-fields-for-variation/plugin.php on line 56
[12-Oct-2018 20:02:01 UTC] PHP Warning:  Invalid argument supplied for foreach() in /home/website/public_html/wp-content/plugins/woo-custom-fields-for-variation/plugin.php on line 56
[12-Oct-2018 20:08:04 UTC] PHP Warning:  Invalid argument supplied for foreach() in /home/website/public_html/wp-content/plugins/woo-custom-fields-for-variation/plugin.php on line 56
[12-Oct-2018 20:08:04 UTC] PHP Warning:  Invalid argument supplied for foreach() in /home/website/public_html/wp-content/plugins/woo-custom-fields-for-variation/plugin.php on line 56
[12-Oct-2018 20:08:04 UTC] PHP Warning:  Invalid argument supplied for foreach() in /home/website/public_html/wp-content/plugins/woo-custom-fields-for-variation/plugin.php on line 56
[12-Oct-2018 20:19:54 UTC] PHP Warning:  Invalid argument supplied for foreach() in /home/website/public_html/wp-content/plugins/woo-custom-fields-for-variation/plugin.php on line 56
[12-Oct-2018 20:19:54 UTC] PHP Warning:  Invalid argument supplied for foreach() in /home/website/public_html/wp-content/plugins/woo-custom-fields-for-variation/plugin.php on line 56
[12-Oct-2018 20:19:54 UTC] PHP Warning:  Invalid argument supplied for foreach() in /home/website/public_html/wp-content/plugins/woo-custom-fields-for-variation/plugin.php on line 56