So you accidentally updated to MC 1.4.6?? Oh well, Here's how to fix it for Mac and windows 7/vista (Please note this does not work for windows 8 or Linux, and only if you have a backup drive on a Mac) Windows 7/vista (Before you do this Backup!!!! (To do this when you get to step 1 just create a copy of your .Minecraft)Ok. First thing you need to do is to open your AppData folder, You can do this by typing %appdata% (With the %) into the Start Menu and going to your 'Roaming folder'Next you want to find the folder marked '.Minecraft' and double tap it to open itNow your in, Right click the 'bin' and select 'Properties'Next you want to select Previous VersionsAfter it searches for previous versions it should come up with quite a few, Select one that is before you updated. (So if you Updated at 16:00 you want to pick the one before then.If however, it shows no previous versions, you will need to turn on System restorehttp://helpdeskgeek.com/windows-7/windows-7-enable-system-restore/On how to do this.Then, Just apply and Ok and you should have your Jar back Windows 8Due to the infinite genius of microsoft, this does not work for windows 8 - You'll have to MCnostalgiahttp://www.minecraftforum.net/topic/106402-tool-cyborgs-tools-mcnostalgia-104/MAC NOTE: The following method only works if you have a backup drive enabledHow to do it if you have Time Machine enabled:1. Open the bin folder.2. Go to Applications and click on Time Machine. Your desktop will appear to slide up, with a lot of windows and a galaxy behind. Scroll though the windows until you find a backup before you updated to 188.8.131.52. Click the window. The bin folder will restore, and you'll be back in 1.4.5!A tip for all OSes: If you have some space to spare, before you update in the future, drag the old jar to a folder. That way, you can swap jars if you need them or feel nostalgic in the future.Thanks to SpaceShuttleFan for the info on how to do it on a mac. LINUXThere is no way to revert a file in Linux, You'll have to use MCnostalgia.http://www.minecraftforum.net/topic/106402-tool-cyborgs-tools-mcnostalgia-104/FAQsQ. Why not just use MCNostalgiaA. MCNostalgia downloads over 100MB's of Jar files to your PC which can take a while. This provides a much faster and easier alternative and also allows you to keep your mods.Q. It doesn't work. There is no Older versions in the previous options tab.A. You need to turn on System Restore so in future it will work. But you will have to use MCNostalgia this time.Q. ZOMG@!@! I lost my Bin folder I hate you@!A. I told you to backup >.<Q. Does this work in linux?A. There is no way to revert a file in Linux, You'll have to use MCnostalgia.Please note, This is a remake of this thread. http://empireminecraft.com/threads/accidentally-updated-read-this.5604/I am in the process of updating everything on here.