You are correct. Still cool tho.

I then read about an "obvious O(1) solution" in a comment of the first solution I saw. Thought about it. Solved it in O(1). Thus ignore this solution lol

Works again for me

This seems to be a problem with codewars at the moment, as every Kata I try has this problem currently.

Yes, I'm also getting "unauthorized" on any kata I try at the moment. This seems to be a problem with codewars, not this kata.

The dictionary method needs to instantiate a "useless" dictionary. This one does not.

I was also getting errors outside of my code initially, as under certain circumstances I was returning null in my frequencies method - javascript
How I found my problem is by printing every method call and input, try doing that

Late answer, sorry. Hope you're still up for the challenge!
The problem is that the compiler doesn't know if inside of the foreach something will be returned, so you'd just need to return anything after the foreach, or throw an exception. Then your code should compile

That's actually quite smart

lol

no, as it checks if parantheses is 0 in the end. You do it with an if, this solution returns whether parantheses == 0

you can use

"needle".equals(haystack[i])

which will be false if haystack[i] is null, instead of throwing a NullPointerException

lol

well it's not better necessarily