I have the same issue, it says "the archive is either in unknown format or damaged". Did you find a solution?
I am, yes. The file type is showing as "WinRAR archive" while most other files show as "WinRAR ZIP archive" and i've tried WinRAR and 7-Zip and nothing (I don't know if this is relevant but I just thought I'd mention it)
Edit: WinZIP worked. I got an error message saying some file was not working correctly but it managed to extract the game regardless and it´s working. I don't know if this will cause any problems with the game but everything is working great so far.