License information is invalid

My Little brother recently decided to mess around with the minecraft files in the %appdata% folder. Deciding it needed to be cleaned he took it upon himself to delete a bunch of folders including the “Unity” Folder inside the roaming folder. Now when i launch unity i get an error: “Unity License information is invalid” I can find no solution, i have uninstalled and reinstalled 3 times and nothing is working please help! I would Appreciate it greatly!

It seems that these files are on these locations now

/Library/Application Support/Unity/Unity_v4.x.ulf (OS X)

C:\ProgramData\Unity\Unity_v4.x.ulf (Windows)

more info

I have this problem here, first I have the “.0f3” installed and the editor crash when I applied a script to a prefab component, so I download the patch “.0p5” and it not solve the problem, so, Iam confuse about how patch I need to install.
Now I is reaisntaling the editor following the answer posted for our friend @Ben-Stoneman, and when concluding I will post the result here, but I forgot to restart my computer, so this is really necessary or the installation will work, its because is very very slow the download velocity.

Give the steps below a try. The files may be hidden so ensure you show hidden files.

  1. Uninstall Unity.
  2. Delete This file:
  • WinXP/Vista: C:/Documents and Settings/All Users/Application Data/Pace Anti-Piracy/License Files
  • Win7: C:/ProgramData/PACE Anti-Piracy/License Files
  • Mac: HD/Library/Application Support/PACE Anti-Piracy/License Files

  • Windows: C:ProgramData/Unity

  • Mac: Library/Application Support/Unity

  1. Restart
  2. Download Unity again from the website, since your original install might be corrupt.
  3. Reinstall and test