Fatal error activating the plugin

Fatal error: Uncaught Error: Cannot use object of type WP_Error as array in /home2/mazzafer/public_html/tripcar/wp-content/plugins/exchange-rates-adce/__class/setup.php:55 Stack trace: #0 /home2/mazzafer/public_html/tripcar/wp-content/plugins/exchange-rates-adce/hooks.php(17): Exchange_rates_adce\Setup::install() #1 /home2/mazzafer/public_html/tripcar/wp-includes/class-wp-hook.php(286): exchange_rates_adce_install(”) #2 /home2/mazzafer/public_html/tripcar/wp-includes/class-wp-hook.php(310): WP_Hook->apply_filters(”, Array) #3 /home2/mazzafer/public_html/tripcar/wp-includes/plugin.php(453): WP_Hook->do_action(Array) #4 /home2/mazzafer/public_html/tripcar/wp-admin/plugins.php(180): do_action(‘activate_exchan…’) #5 {main} thrown in /home2/mazzafer/public_html/tripcar/wp-content/plugins/exchange-rates-adce/__class/setup.php on line 55

Hi there! any help on this? thanks!