rawrrgrrl on "[Plugin: 1000°ePaper] can't register - white page"

I can't register my installation.

"NetworkError: 500 Internal Server Error - http://b75.pomodoro.com/wp-admin/admin.php?page=epaper_apikey"
PHP Fatal error:  Class 'SoapClient' not found in /var/www/vhosts/pomodoro.com/subdomains/b75/wp-content/plugins/1000grad-epaper/lib/epaperApikeyApi.php on line 83, referer: http://b75.pomodoro.com/wp-admin/admin.php?page=epaper_apikey

http://wordpress.org/plugins/1000grad-epaper/