It seems that you did not understand the task correctly.

Basically you are expected to reimplement Python's map( ) function with a little bit of additional requirements.
The way how map works, it accepts a mapping function, and a (for sake of simplicity) list. Mapping function is expected to accept one element of the list, and return its value mapped in some way. In your solution, however, func accepts whole list, transforms it, and returns a list back. It's not how mapping function is expected to work.

Kata itself indeed does not help you, because error messages are not helpful at all, and there are actually no helpful assertion messages. If that's something you'd like to complain about, raise it as a separate, specific issue.

I just tried the kata and there was no problem for me. Could you share your code (remember about spoiler flag and markdown formatting), so we could check?

you're welcome :) (...but don't forget the spoiler flag! ;) )