Stuck on a challenge :-/

Im on part two of the challenge where its asking me to create a conditional that allows the program to detect incorrect day inputs for months that only have 30 days instead of 31. I completed the step and ran it with no issues. However, it will not allow me to go to the next step. It keeps giving me this error: "Hmm, the 31st of April? That doesn't sound right. Check that your program prints an error for April (month 4) if the day input is 31." (BTW I put in the 31st of April and it still gives me this message.)