Fatal Error Uploading Pro

I have now managed to add the dashbaord plugin but now I am having issues activating the SMUSHPRO plugin as I am served with a fatal wrror...

Fatal error: Cannot redeclare i18n() (previously declared in /home/yournest/public_html/wp-content/plugins/wp-smushit/wp-smush.php:278) in /home/yournest/public_html/wp-content/plugins/wp-smush-pro/wp-smush.php on line 276

Can you please help?

Thanks