Consider the following code:
module Main where
data Foo = Foo {
  bar :: Int
, baz :: Int
} deriving Show
main :: IO ()
main = do
  let foo = Foo {
        bar = 0
      , baz = 0
      }
  putStrLn $ show fooAfter you go to the line with "baz = 0" and press Enter, Emacs displays "Illegal token: layout-item" in statusbar and indentation no longer works after this point.