We've been seeing this issue on fresh builds - I think .35 was the last one that didn't have problems.
The cause seems to be improper permissions on some items in the user folder.
Check ~/Library/Group Containers/UBF8T346G9.Office to see if it's owned by root. Mine was.
Here is the snippet we used to fix the issue:
username=$(/usr/bin/python -c 'from SystemConfiguration import SCDynamicStoreCopyConsoleUser; import sys; username = (SCDynamicStoreCopyConsoleUser(None, None, None) or [None])[0]; username = [username,""][username in [u"loginwindow", None, u""]]; sys.stdout.write(username + "
");')
groupname=`stat -f%g /dev/console`
for USER_HOME in /Users/*
do
USER_UID=`basename "${USER_HOME}"`
if [ ! "${USER_UID}" = "Shared" ] && [ ! "${USER_UID}" = "adminaccountname" ]
then
if [ -d "${USER_HOME}"/Library/Preferences/ByHost ]
then
/bin/chmod -R 700 "${USER_HOME}"/Library/Group Containers/UBF8T346G9.Office
/usr/sbin/chown -R "${USER_UID}":"staff" "${USER_HOME}"/Library/Group Containers/UBF8T346G9.Office
ScriptLogging "Modified "${USER_HOME}" for user "${USER_UID}""
fi
fi
done