Locations was removed in Ventura, I believe? I also don't want to change DNS servers, I want to add custom DNS entries, which I don't believe Locations supported?

Didn't seem to work for me.

Checked and repaired permissions on boot drive. Not really that keen on backing up and clean installing -- may just leave it on Mavericks if it comes to that, at least for now. Or move it over to whatever comes after Yosemite.

Downloading installer yet again, hoping that it's been updated with 10.10.3 and maybe fixed whatever's not happy.

Ran it again, got to the the progress bar after reboot, watched it go for about five minutes (from about 45 minutes down to about 40 minutes remaining), went away, came back, and the Mavericks login screen is back. Don't know how far it got. Guess I'll have to watch longer next time.

The first time I tried the installation, it was from a saved installer. The second time, I downloaded it fresh to see if it made a difference. It didn't. The HTPC is a Mac Mini Server mid-2011 hooked up to my TV, a Drobo, and an Apple wireless keyboard and magic trackpad. Next time I try, I'll time the elements.

Mac Mini Server, Mid-2011; seems to be compatible.

FWIW, I was just able to 'Back to My Mac' from a Yosemite computer to a Mavericks mini behind my firewall. I haven't upgrade the Mini to Yosemite yet, so I can't test that.

I used their Mac OS X Feedback webpage. Fingers crossed.

And, to be honest, the sharing features are recently added -- this seems to be one of the areas they /are/ focusing on.

I'm hoping to stick with Mail.app, even if it means waiting for a fix.

I have that checkbox, yeah. Neither setting seems to affect link placement for me on Yosemite. I feel like this used to the job -- and some Google searching implied that it did.