How to hack RIGHT HERE: When windows, go here. From there you download it, ones its downloaded you drag and drop the download to your desktop. Ones you have done that you will get a zip file like this with the name: "Huzuni" behind it. When you don't have this, you download winrar. download that, and re-download the file. Now you have this on your desktop: . You right click that and click: pack out here. Ones you have done this you will have this: Now you open your minecraft folder by typing Windows + r. This will apear: There you type: %Appdata% and hit enter. You click . there you go to and drag and drop the into it. Now you open minecraft, and . There you choose: If this isn't there, you re-run minecraft. After it's there you start minecraft, now you have hacks, DONT use the illegal ones. type shift in game and you can choose hacks If the huzuni says your client is outdated, then go here and download a later version, repeat the steps from above here when you do this I hope this worked out for you. Here's a video for explinations: ~Jimmeh
to people reading this, it dosent have to be huzuni there are tons of clients to explore. also, here are which are illegal/legal and where they can be used. list needs updating though http://www.skyblock.net/threads/acceptable-hacks.11728/
check everything first. it should be unzipped and that unzipped folder (or contents of the zipped folder) be placed in versions (place in versions, do not place in any folder inside the versions folder) next step would be starting minecraft, youll see the screen where it says minecraft news and whatnot, find the edit profile in bottom left, go to use version, and find huzini or whatever client your using, click it then save profile also making sure its a current version, not outdated (i reccommend making a 2nd profile so you have vanilla and client versions seperate) after that, it should work... idk sorry :/
Maybe download a later version of it, maybe re run minecraft?... Or maybe wait some minutes till it runs, i had the same problem, but because of a reason unknown to me it did worked inventually