wp php error

Hi,

While cleaning up our installation, we found the plugin having an error:

wp_enqueue_style was called incorrectly. Scripts and styles should not be registered or enqueued until the wp_enqueue_scripts, admin_enqueue_scripts, or login_enqueue_scripts hooks. Please see Debugging in WordPress for more information. (This message was added in version 3.3.0.)

wp-includes/functions.php:5167
_wp_scripts_maybe_doing_it_wrong()
wp-includes/functions.wp-styles.php:171
wp_enqueue_style()
wp-content/plugins/simple-excel-pricelist-for-woocommerce/classes/sepwSettingsPage.php:35
sepwSettingsPage->__construct()
wp-content/plugins/simple-excel-pricelist-for-woocommerce/simple-wc-excel-pricelist.php:23

Regards,
Sven