Sounds like you went to Maintenance, Start New Year. Which you then picked new fiscal year or if the program defaulted to that, you didn't switch to new Calendar year.

Just change the session date to Jan 1 or 2 or 3 or what you want and move on (if you calculate payroll in the program and you have not completed all payroll for 2015, do that first).

You cannot change a session date to any date within the previous fiscal year so the program is doing what you should expect. However, you should have been able to post an entry in the previous year (before Jun 1/16) unless you had the date lockout turned on. You didn't tell us what the program indicated as the message when you tried, so I can't help any further on that.

You have it sorted out now.