PHP Error

I keep getting the following error on my charts

Notice: Undefined index: chart-title in wp-content/plugins/productsize-chart-for-woocommerce/admin/includes/productsize-chart-add-meta-form.php on line 47

Notice: Undefined index: chart-image in /wp-content/plugins/productsize-chart-for-woocommerce/admin/includes/productsize-chart-add-meta-form.php on line 48

Notice: Undefined index: chart-position in wp-content/plugins/productsize-chart-for-woocommerce/admin/includes/productsize-chart-add-meta-form.php on line 49

Notice: Undefined index: chart-content in wp-content/plugins/productsize-chart-for-woocommerce/admin/includes/productsize-chart-add-meta-form.php on line 50

Notice: Undefined index: chart-table in wp-content/plugins/productsize-chart-for-woocommerce/admin/includes/productsize-chart-add-meta-form.php on line 51