2 months without any problem. Now again I have the same php warning showing up... strange.
The wysiwyg-plugin checks if userid exists:
$cookieid=isset($userid) ? qa_cookie_get() : qa_cookie_get_create();
The badges plugin on the other hand, does not:
qa_remote_ip_address(), $user_id, $handle, qa_cookie_get_create(), 'badge_awarded', ...
Could this be causing problems?
Edit: Found in the error log another line, causing this issue:
headers already sent by (output started at /qa-include/qa-theme-base.php:79) in /qa-include/qa-app-cookies.php on line 61