In my case I believe the failure of the last step of the WP 4.4 upgrade on Godaddy/Plesk- which caused key tables not to be added to the mySQL database, was due to an ongoing "access rights" issues. This is the reason many staff at Godaddy repeatedly advise switching websites from Plesk/Windows to Linux.
Hopefully the fix now provided by Plesk to Godaddy will solve this once and for all.
My own question is will this be applied automatically to all shared servers. And will godaddy inform me when completed so I can try to upgrade again?