I'm a simple user of code forces. Last Month I saw that I can't visit code forces and then I contact my isp. After my isp investigations, they said that the problem is not from their side. Then I have nothing to do so I change my ISP and then everything was okay. I was able to use cf regularly as my need. But From last Day I face the same problem again (attached the problem screenshot)!
So again I inform this problem to my new isp, and then they check and said that code forces block my IP address. After a long conversation with my isp, they change my IP address and now I can visit cf.
But the question is that why cf block my IP address? Cause I don't do anything that goes to against code forces rules! ScreenShot