Yup, this got me too. The description ought to make explicit the requirement that there be no newline character at the end.

Your English is perfecly fine, don't worry. :) Yes, preloaded MORSE_CODE is a bit different from Wikipedia page (for example, it contains SOS as a single signal).

The point of this kata is not in copypasting of data from Wikipedia, the point is creating a correct algorithm using existing data, whatever they are.

As for your Unknown error, I could suppose 3 reasons for that:

1. Connectivity problem, it happens here on CodeWars. Try reloading a page.
2. The kata launcher for the particular language may be down, try again in an hour or two, or the next day.
3. Make sure you're submitting the solution for the correct language. It could be lots of fun trying to fix a piece of JavaScript code that for some reason doesn't work when submitted as Java code. :)

Your example doesnt work for me :(
When im using MORSE_CODE in my code im getting "Test didn't pass: Unknown error".

OK, i created my own MORSE_CODE array based on wikipedia, now im getting "SOS THE QUICK BROWN FOX JUMPS OVER THE LAZY DOG,', expected 'SOS! THE QUICK BROWN FOX JUMPS OVER THE LAZY DOG." Curiously, i think preloaded MORSE_CODE is different from a wiki morse. How can i get the correct(?) value so that I could pass that test

(sorry for my english im 11 year-old schoolboy from bangladesh)

I don't want debate about semicolons but I just don't like them. I found my code cleaner without it.

Just like that, it's a global variable.

Same problem I guess ^_^' Extra newline at the end of pattern string(output).