I got the same and "solved" it by including \t as an acceptable character. It's a bit weird.

You should ensure that whatever outside system you're using, that it in fact has the correct expected values for the given input. For example, your code fails the 5th fixed test. What answer does PyCharm have for that one? Does it match Codewars? Does all the input match? Once you certify all that, you can debug why your code fails that one particular test.

Better yet, just work on site only, that will simplify things greatly.

Your code fails the very first test because it doesn't recognize that Alice DOES have a word that can be a mutagram for the starting word aver; in that she knows the word over which can be mutated from aver at the first letter.

No matter what, don't give up!

Hello, welcome to Codewars. I'm glad your're enjoying the kata.

I looked at your code and found that your method does not adhere to one of the rules: a valid response word must contain four unique letters.