Migration from 4.7 to ECC 6.0 - Deactivate Update of Classic General Ledger

My client has migrated from 4.7 to ECC 6 version. In the ealier version we had a report developed in FI Module, which was created as a local object.

Now when we are trying to activate the same development in ECC 6.0 and I am trying to use the dynamic selections option of this report, system is throwing an error and taking to this customisation node :

Fin Accounting Global Settings (New)->Tools ->Deactivate Update of Classic General Ledger (GLT0).

Can I know the implications of this option ? Can I deselect the check boxes mentioned in this node ? What could be the consequences ?

Please guide me.

Thanks

Ravi