Admin Dashboard: Deprecated Creation of dynamic property FS_User

Hi,

When using the admin dashboard in WP – Webba Booking, I see the following errors (using Query Monitor plugin). Can you please look into this?

Deprecated Creation of dynamic property FS_User::$is_beta is deprecated
wp-includes/functions.php:650
unserialize()
wp-includes/functions.php:650
maybe_unserialize()
wp-includes/option.php:247
get_option()
wp-content/plugins/webba-booking-lite/freemius/includes/managers/class-fs-option-manager.php:173
FS_Option_Manager->load()
wp-content/plugins/webba-booking-lite/freemius/includes/managers/class-fs-option-manager.php:98
FS_Option_Manager->__construct()
wp-content/plugins/webba-booking-lite/freemius/includes/managers/class-fs-option-manager.php:134
FS_Option_Manager::get_manager()
wp-content/plugins/webba-booking-lite/freemius/includes/class-fs-options.php:90
FS_Options->__construct()
wp-content/plugins/webba-booking-lite/freemius/includes/class-fs-options.php:68
FS_Options::instance()
wp-content/plugins/webba-booking-lite/freemius/includes/class-freemius.php:3391
Freemius::_load_required_static()
wp-content/plugins/webba-booking-lite/freemius/includes/class-freemius.php:2809
Freemius::instance()
wp-content/plugins/webba-booking-lite/freemius/start.php:553
fs_dynamic_init()
wp-content/plugins/webba-booking-lite/webba-booking-lite.php:36
wbk_fs()
wp-content/plugins/webba-booking-lite/webba-booking-lite.php:58
3 Plugin: webba-booking-lite