Thank You everybody for your help. I got my iMac Desktop in 2013. I don't know what a security update is. I'm not on the Internet with my Mac because I don't want any hacker on my machine. And that is why everything has stayed the same. I know little about updating anything. All I know is that updating can cause other things...camera, OS, programs, external devices not to be supported etc etc. and that is why I would like to tell a tec what I have and they could know better what would work and not, and what I had to do to pull this OS and LR update off. Other things I have may have to be updated. I just had to buy a new macro lens because of an accident and what if I wanted or needed to buy a newer camera, not the same model I have had. And how long do I have before the cameras I own are not covered (?) I've learned some of Lightroom and am running it very well for my purposes and I don't want that to end. But nothing sits still and I'm not knowledgeable in this. So I hoped I could list out what I have and someone here (hopefully without too much trouble) can tell me what to check out to see if it will run with these new updates or is history. And any further costs. And I hope I don't have to buy a newer computer for awhile! And I wasn't planning on doing this updating just yet...and I don't know about that either. This is why I have not updated, I'm scared of the Internet, I don't care if I have a Mac. Someone or something could get through. So I am perfectly happy running LR on my own and I dread having to update anything and everything. It's kind of funny, but that is my quandary.