Firewall causes sshd to fail: ForceEnableHack

If I turn off the Firewall in Yosemite, then the SSH daemon runs fine. If I turn on the firewall, then the SSH daemon fails to run. The problem is with launchd apparently finding crap in a plist file, and aborting. I've searched in every plist file on my computer and can't find the source of the problem.

sudo find / -xdev -name '*.plist' -print0 | sudo xargs -0 -t -n 1 plutil -convert xml1 -o - | grep ForceEnableHack

In the console I see these errors:

com.apple.xpc.launchd[1] (com.openssh.sshd): Unknown key for string: SHAuthorizationRight
com.apple.xpc.launchd[1] (com.openssh.sshd): Unknown key for Boolean: ForceEnableHack

I "fixed" the SHAuthorizationRight problem by editing the /System/Library/LaunchDaemons/ssh.plist file and removing that. But what is ForceEnableHack and how to get rid of it?