Okay - I found the problem. I get the text from the server and somehow are \n and \r added which I did not see in Intellij Idea.
var fixedString:String = explanation.getDescription().replace(new RegExp('\\n', 'g'), '').replace(new RegExp('\\r', 'g'), ''); fixes it -- Sent from: http://apache-flex-users.2333346.n4.nabble.com/