Version 2.0.0 BETA 5 FATAL ERROR on activation

when activating, it triggers a fatal error, my whole site is useless now

Plugin could not be activated because it triggered a fatal error.

Fatal error: Cannot use object of type WP_Error as array in /home/<USERNAME>/public_html/wp-content/plugins/2kb-amazon-affiliates-store/lib/kbAmzApi.php on line 65

https://wordpress.org/plugins/2kb-amazon-affiliates-store/