fiscal year closing ax 2012

For fiscal year end closing, when i open GL>Periodic>Fiscal Year Close>Open Transactions system will prompt a warning infolog. The message is to turn on a Posting definitions setting in the GL Parameter, below :

"Posting definitions are required for year end general ledger close. Select the 'Use posting definitions checkbox on General ledger parameters.'"

 And i have trun off and remove the Public sector configuration in the system. But, this warning infolog still happened when i open the Open Trasactions Form.


What the impact if i turn off the public sector from the system?