Fatel Error on Plugin Activation

I deactivated the Drift plugin and when I re-activated it I get a fatal error message:

Fatal error: Uncaught Error: Using $this when not in object context in /nas/content/live/tnsstaging/wp-content/plugins/drift/includes/class-drift-main.php:656 Stack trace: #0 [internal function]: Drift_Main::release_updates(”) #1 /nas/content/live/tnsstaging/wp-includes/class-wp-hook.php(286): call_user_func_array(Array, Array) #2 /nas/content/live/tnsstaging/wp-includes/class-wp-hook.php(310): WP_Hook->apply_filters(”, Array) #3 /nas/content/live/tnsstaging/wp-includes/plugin.php(465): WP_Hook->do_action(Array) #4 /nas/content/live/tnsstaging/wp-admin/plugins.php(177): do_action(‘activate_drift/…’) #5 {main} thrown in /nas/content/live/tnsstaging/wp-content/plugins/drift/includes/class-drift-main.php on line 656