Out of th eblue I can't edit or create any posts anymore because whenever I try to call post.php all I get is a white screen! I know I'm using a fairly old version of WP but so far it has been working fine and I haven't changed anything (no plugins etc.) on the system - it just happened today!
I tried things like deleting the cookies - no succes
I also deactivated and reactivated the wysiwyg editor - no succes