WordPress version: 3.5.1
WordPress SEO version: 220.127.116.11
Error message after installing wpseo on fresh install (with installatron):
Warning: Cannot modify header information - headers already sent by (output started at /home/internet/domains/zoekmachinemarketingdiensten.nl/public_html/wp-admin/includes/template.php:1642) in /home/internet/domains/zoekmachinemarketingdiensten.nl/public_html/wp-includes/pluggable.php on line 876
Then I installed Fast Secure Contact Form and then my blog was not able to load anymore, I got blanco screen. But the second time I did exact the same and I still got error message but my blog is still running (cross my fingers).