If a quotation mark disappears the color coding of the facelet page should be toggled to black to help with error detection when writing code. The red x on the left is nice, but it is hard to know if things are coded correctly. The attached screen shot shows a missing quotation mark on the tag: <ui:define name=body"> It would be nice if the body text would turn black letting you know it was not parsing, or if it could be underlined in red as the possible problem.