I would like to give some feedback about Run & Check

My code seemed to pass the Test 4/4(checkio(2,9)), but the Check does not proceed anymore.

My result: "01,23,45,67,80,12,34,56,78"

From: http://www.checkio.org/mission/auto-painting/solve/

HTTP_USER_AGENT:

Mozilla/5.0 (Windows NT 6.1; WOW64; rv:38.0) Gecko/20100101 Firefox/38.0