So there should be an algorithm to take off the solutions that don't pass new tests, no ?
If not, it's misleading to read solutions not working anymore.

Yes they were.

This solution doesnt work because it fails for
negative numbers : 1.2.3.-7

And also for strings with more than 4 groups of number with anything other than numbers as: 1.2.3.4.z

How has this solution passed the kata ?
Maybe the tests were different at the time ?

Thanks for the explanation.
The kata wasnt clear at all for me neither.
Because of the narrow fonts as you said.

I think someone should modify the kata Description to make it clearer, by explaining with text, or by changing the results to "unnarrow" it if its possible, or by providing an image.