Already updated. To see the change, copy your code somewhere, click reset in the Kata trainer, paste your code back and re-try.

Edit: I've just realized that the description didn't cover that spaces can be absent when it doesn't introduce ambiguity.
Will update test cases.

Original post:

Is it really a parsing failure? I don't think so. It's a valid Lisp expression.

How is that ill-formed? Could you provide a better one? Test cases are intented for catch edge cases.