I live in China, my Hub before could still load even if the youtube video was blocked. I could get my rewards are dlc cars. But now it's over 2 weeks and the HUB doesn't work at all! It says Forza Hub is UNAVAILABLE. There's also a thread about this in the official forza horizon 2 forum (I don't know if I can paste the link here, just go check it). I followed all the instructions to try to solve the problem: hard shut down, uninstall and re-install, change dns etc... Nothing.
They told me I could still get the rewards from the website https://rewards.forzamotorsport.net/en-US but now here I see that to get some cars you needed the application. I fear for some new FH2 and FM6 content if they don't fix this.
Forza Hub ain't working in all regions where YouTube doesn't work. I've been getting the exact same message since the FM6 message started popping up. Before that, it used to work without any issues whatsoever.
For now, you'll have to get rewards from the official site. Until FM6 gets released, The Hub isn't working. So relax, and look forward to the FM6 demo.