Fatal error once speaker-lite installed

Hello ,

When I install your free speaker-lite plugin on my Website , it crashes my website and I get the following error message :

Fatal error: Uncaught Error: Class 'Merkulove\SpeakerLite\MobileDetect' not found in /var/www/html/academypedia/en/wp-content/plugins/speaker-lite/src/Merkulove/SpeakerLite/AssignmentsTab.php:781 Stack trace: #0 /var/www/html/academypedia/en/wp-content/plugins/speaker-lite/src/Merkulove/SpeakerLite/AssignmentsTab.php(482): Merkulove\SpeakerLite\AssignmentsTab->Devices(Object(stdClass)) #1 /var/www/html/academypedia/en/wp-content/plugins/speaker-lite/src/Merkulove/SpeakerLite/FrontStyles.php(71): Merkulove\SpeakerLite\AssignmentsTab->display() #2 /var/www/html/academypedia/en/wp-includes/class-wp-hook.php(303): Merkulove\SpeakerLite\FrontStyles->enqueue_styles('') #3 /var/www/html/academypedia/en/wp-includes/class-wp-hook.php(327): WP_Hook->apply_filters(NULL, Array) #4 /var/www/html/academypedia/en/wp-includes/plugin.php(470): WP_Hook->do_action(Array) #5 /var/www/html/academypedia/en/wp-includes/script-loader.php(2083): do_action('wp_enqueue_scri...') #6 /var/www/html/academypedia/en/wp-includes/class-wp-hook.php(303): w in /var/www/html/academypedia/en/wp-content/plugins/speaker-lite/src/Merkulove/SpeakerLite/AssignmentsTab.php on line 781
There has been a critical error on this website.

Could you help me solve this problem quickly please so that I could buy you paid version .

Thank you