Learnpress 4.2.0 REST error

with latest Learnpress we have this error in the log:

[17-Jan-2023 09:47:11 UTC] PHP Fatal error:  Uncaught Error: Cannot use object of type LP_REST_Response as array in /homepages/42/asd/htdocs/aaa/wp-content/plugins/bp-better-messages/inc/rest-api.php:56
Stack trace:
#0 /homepages/42/asd/htdocs/aaa/wp-includes/class-wp-hook.php(308): Better_Messages_Rest_Api->catch_unauthorized(Object(WP_REST_Response), Object(WP_REST_Server), Object(WP_REST_Request))
#1 /homepages/42/asd/htdocs/aaa/wp-includes/plugin.php(205): WP_Hook->apply_filters(Object(WP_REST_Response), Array)
#2 /homepages/42/asd/htdocs/aaa/wp-includes/rest-api/class-wp-rest-server.php(465): apply_filters('rest_post_dispa...', Object(WP_REST_Response), Object(WP_REST_Server), Object(WP_REST_Request))
#3 /homepages/42/asd/htdocs/aaa/wp-includes/rest-api.php(410): WP_REST_Server->serve_request('/lp/v1/courses/...')
#4 /homepages/42/asd/htdocs/aaa/wp-includes/class-wp-hook.php(308): rest_api_loaded(Object(WP))
#5 /homepages/42/asd/htdocs/aaa/wp-includes/class-wp-hook.php(332): WP_Hook->apply_filters(NU in /homepages/42/asd/htdocs/aaa/wp-content/plugins/bp-better-messages/inc/rest-api.php on line 56