Can't get SEO PACK to work

I can’t enter title & description in the all-in-1 SEO pack boxes; just won’t let me. I use a Mac. I had another person login with a pc and he could do that. I’m not sure what version I have (how do you see that?) but am pretty sure I don’t have the latest but when I click on newest version it says I need to download something. Would GREATLY appreciate help asap! Thanks.