See the FAQ:
http://leecher.freddy.lt/faq.php?expand=faq206"Failed to find message" - wrong custom selector in "Message" tab.
"Failed to find messages" - wrong custom selector in "Subject with URL" tab.
Those are two different errors. You have wrong selector for "Message" (not "Subject with URL").
Go to "WEBSITES" -> select that website -> "Selectors" tab -> add these selectors:
Subject:
Code:
h2#title
Message:
Code:
div#content
Subject with URL:
Code:
div.link
Remove elements (one per line):
Code:
div#title_desc
div[style*=width: 100%]