Messages extension in the share menu does not work.
EG: In Safari > File > Share > Messages .... nothing happens. Should open Messages.app and allow me to forward to a contact.
Same problem with all apps that support this feature. EG: Can't share a photo from Photos.app in same way.
NOTES:
System Preferences > iCloud > Contacts > Off > then retry and it works
System Preferences > iCloud > Contacts > On > then it does not work again
STEPS TAKEN SO FAR WHICH HAVE NOT SOLVED THE PROBLEM
Share button shows “No Service” menu items missing or has other issues?
https://support.apple.com/en-us/HT203129
If this doesn’t help, backup the computer and reinstall macOS Sierra from OS X Recovery.
https://support.apple.com/en-us/HT204904
Start up in Safe Mode. https://support.apple.com/kb/PH21875?locale=en_US
and then Repair Disk. https://support.apple.com/kb/PH22243?locale=en_US