I'm trying to add a new rule in the Game Manager to execute a function on event type 'com.playfab.player_logged_in'. However, when I try to save it, it says there are 'some errors on this page' and gives me a message "An error occurred while loading data from the server. PlayFab engineers have been notified of the issue and will investigate." But it doesn't highlight which bit of the rule I need to fix.