I have had the Roaring Heights saved game for about a year which means that after the Error 12 (happened about five months ago) I decided not to play it because I thought that I could get the "Serious Error" message while loading the saved game which had been restored at a previous save date.
There is a 99,9% case (to me) that the town that the error 12 occurred might have been corrupted when it comes to loading it again and starting a new game from scratch and because of that I need to reinstall Roaring Heights again, I think.