Lr 5.7 Update Won't Install

I'm being told to Quit because I don't have Ps CR 5.4 installed. When I go to the support section I see a lot of 5.6 and God knows what else, but no 5.4 for macintosh so I am able to update my Lr 5.  I thought subsequent installs incorporated the previous installs, for I did instal CR 8.6 (was it that not too long ago). 

Can you help me get the link to the needed download for Lr 5.7 update for Macs.

Thanks.

Bill