Mac Tips: How to disable 'open safe files after downloading' in Safari for Mac

Got an Apple, Mac or iOS tech question? We have the answer. When you use Safari to download files - music, movies, images - it's usually a simple matter to decide if they'll open automatically once they're on your computer. But this time we have a reader who's having trouble getting that function to work. Luckily, we have a Plan B.QuestionI am using Safari 8.0 on an iMac running Yosemite 10.10.1 and the "Open 'safe' files after downloading" is greyed out so that I cannot uncheck it. I