For your Horizon opening issues please check for some possible solutions here: https://community.wemod.com/c/horizon/support
What DLCs are you trying to get for free? There’s only a small selection of them that are available if you don’t have a Jtag or RGH modified 360. They’re DRM free versions, and you’ll need a program like WinRAR or 7-Zip to extract the DLC file from the individual part files you download, if you’re lucky you’ll find it as one file that’s ready to drag into Horizon and add to your device. I’ll leave a few links below to all the DRM free content that I know of, some links might be dead but that’s just how it is with this kind of stuff. If you need more help feel free to PM me or reply in this topic.
Kill Seth DRM Free Stuff: http://www.zippyshare.com/kill_seth
Aden34’s DRM Free Thread: Aden34’s DRM Free Thread. NEW LINKS! (Bioshock Infinite)