Create Newsletter link not working

Plugin - eNewsletter
I have upgraded to 2.3.5 - when I Click on Create Newsletter - i just get a blank page. Please help asap - I have to get a newsletter out today!
Thanks,
Tasha

The page that is blank is:
http://streambenefits.com/wp-admin/customize.php?wp_customize=on&theme=StreamBenefits&newsletter_id=25&return=admin.php%3Fpage%3Dnewsletters