GTA 5 not in modding after upgrading to diamond?

Hey everyone, I am new to this forum and I downloaded horizon but it says its offline. I paid for the diamond subscription and its still doing the same thing. I am trying to mod gta 5 on the 360. thank you!

Double check to make sure your Anti Virus isn’t blocking Horizon from connecting to the Internet. Just disable it until you are done modding GTA in Horizon.

Your firewall and or anti virus could be conflicting with Horizon. Please insure that Horizon is white listed and or made an exception through both.