I am trying to send a test newsletter through simplenews and it logs me out from my website everytime I hit the send button. I am logged in as admin. I have successfully sent test newsletters before and I dont think it is a permissions issue since I have necessary permissions. The only thing I changed was install simplenews related modules like simplenews-statistics,etc. I also copied the .tpl.php files from simplenews's module folder to my theme folder.
What could be the problem?