This may be related to the browser you are trying to use to download the software on, I would first suggest trying a different browser to download the game.
Error 12 usually means that there was a misconfiguration or it failed to launch the installer, You could try clearing your temporary internet files and running a clean up to get rid of any corrupt installers that are already present.
It can also be related to where the browser is trying to temporary store the file, choosing to save the file into a different location may help avoid this.
A_K i have not seen before, If the problem persists i would advise including a screenshot or the error message you are receiving.
You can also attempt to download the game from this threads