Cannot send session cache limiter – headers already sent

and

Cannot modify header information – headers already sent by

Very annoying! I couldn’t spot anything wrong with the files in Notepad or Dreamweaver. I was very confused. So I decided to open the files in my web hosts online text editor. Lo and behold, Expression Web had put some odd characters before the opening PHP tags on a couple of files! I removed the characters in the text editor and now everything is working fine again.

Moral of the story? Microsoft is rubbish!