Stephanie:

It would be hard to say for sure without seeing the data but about the only reason for Warning fiscal year 2012 - ending date is more than 1 day from the start date of fiscal year 2013" is because someone manually changed the fiscal calendar dates.

As for why you are unable to complete the year end successfully, again without seeing the data it's hard to tell. Sometimes the only way to solve these types of problems is to have an expert look.