I just moved (via Migration Assistant from a Time Machine backup) from an 2015 MacBook Pro running OS X 10.11.6 to a (brand new, never used) 2019 MacBook Pro running macOS 10.15.7. All good, but this one unpleasant surprise has me stumped -- that nothing happens when I click the checkbox to activate File Sharing. Nothing. Nothing at all. Just can't check it.
I have no trouble connecting through File Sharing from this new machine to my old 2015 machine running El Cap, or to my daughter's which is running High Sierra. I just cannot get this one to act as a file server.
Googling has been no help at all with this so I'm hoping someone here might have some helpful thoughts.