Removed my last comment after checking my code. It seems like I was giving the correct answer.

For test 14 my code does indeed return false, but it still fails. In my mind "}}]]))}])" is about as wrong as it gets so the test case must have an error.

Test14
Expected: True
But was: False
at BraceTests.Test14 () [0x00000] in :0
input: "}}]]))}])"

I dont understand test 14, could you tell me why it should be true?
Edit: Im using C#

The more knocks the merrier!

This is a great Kata, I actually got this question at a job interview before.