I have not used FIM but in a conventional data load you first select the members of each dimension including time. Your procedure will have a line something like
set period Jan 2014 - nov 2014
alternatively it might say
set period earliest - latest
if your data included rows for December 2014 and latest was set to Nov 2014 then all rows for December will be rejected with the message you are currently getting. If you are using "latest" ten set it to Dec 2014. Alternatively ensure your procedure contains the line.
set period Jan 2014 - dec 2014