Php error for MB User Profile Plugin

Hi,
if I insert a shortcode like
[mb_user_profile_register id="meta-box-id" label_submit="Register" confirmation="Your account has been created successfully."]

I have an error in
wp-content/plugins/meta-box-aio/vendor/meta-box/mb-user-profile/src/Forms/Base.php
line 147

I fix editing the line from
$key = ConfigStorage::store( $this->config );
to
$key = \MBUP\ConfigStorage::store( $this->config );

Bye
Alessandro