Hi, I work with Lyx for OS X El Capitan vs. 10.11. I tried downloading and reinstalling Lyx before posting this but the problem remains.
The problem is that when I try to enter mathematical formulas using the menus at the bottom of the screen (e.g. greek letters, arrows, equality/inequality relations etc.) nothing happens: I click on a symbol, e.g. alpha, with no result. I am not sure, but I think this started after I installed El Capitan recently - Lyx has worked perfectly on my Mac for some years now. I've seen reports on this list of problems - different from this one - after El Capitan installation and the remedy seems to be to remove something called System Integrity Protection. I have not tried this - not sure how to do it - and it seems like a really bad solution to the problem. Hope someone can help! Fridrik