Error 2:
Unarc.dll also reflected as "an error occurred while unpacking: archive corrupted/unable to read data (decompression fails)! unarc.dll". Which is quite different from the above error.
This error occurs due to that the software/game setup has some corrupted installers, archives etc so that it cannot be extracted by unarc.dll.
The following codes indicate different issues based on your specs, OS type or even the setup file itself.
Code 1: "INVALID_FUNCTION" and your archive is corrupted
Code 2: "FILE_NOT_FOUND" (i.e) unarc cannot find the file specified
Code 3: "PATH_NOT_FOUND"
Code 5: "ACCESS_DENIED"
Code 6: "INVALID_HANDLE"
Code 7: "STORAGE_BLOCKS_WERE_DESTROYED"
Code 11: "BAD_FORMAT"
Code 12: "INVALID_ACCESS"
Code 14: "OUT_OF_MEMORY"
To avoid this error, try to install the software/game with a new complete setup file which is genuine.
Note1: Don't install any ultra high compressed game.
Note2: Don't install any pirated game.
Note3: The downloaded iso image files of game from any torrent site may work 100% but not for all types of OS with different versions.