I have tested it with my previous solution and it works, read this: https://docs.codewars.com/training/troubleshooting/

Hi! My solution seems right but it returns this error: "undefined method name' for nil:NilClass". It seems that the method on line 13 of the sample tests isn't defined. Is there a way around this?

Because your code returns if the last element of the list is less or equal to limit.