Apple - Process (fmfd) spamming my console with sandbox denies

I just found how to solve this problem.

1. Go to the /System/Library/Sandbox/Profiles folder, you will find a file named fmfd.sb. You can't modify it here, so copy it to your desktop.
2. Open the copy with TextEdit, locate the allow file-read-metadata section and add a new line under (literal "/Volumes") for the folder that can't be read, for you that should be (literal "/Volumes/Macintosh HD").
3. Replace the original with the copy (don't forget to make a backup), since it's in a system folder it will ask for your password.
4. Reboot your Mac the error messages in Console should be gone!

According to Activity Monitor info on fmfd:

This tool generates files that allow Apple to investigate issues with your computer and help improve Apple products. The files might contain personal information found on your device or associated with your iCloud accounts, including but not limited to serial numbers of your device, your device name, your user name, file paths, file names, your computer’s IP addresses, and network connection information. This information is used by Apple in accordance with its privacy policy and is not shared with any other company. By using this tool and sending the results to Apple, you consent to Apple using the contents of these files to improve Apple products.

To see what fmfd is doing sample the process, i.e. open terminal, enter:

sample fmfd

fmfd is 'find my friends daemon' I believe. I have noticed on my multiuser iMac that the two logged in users are polling each other's home directories ... though I've not yet figured out why. :-)