As long as the settlement has not been completed, the changes in the time recording are taken into account in the current settlement.
Go to the final completion of the settlement on 
.
The notice message refers to the fact that no corrections are possible after the settlement has been completed.
You can see that the settlement has been completed by the closed lock.
The open lock represents a settlement that has only been saved but not finalised. It is possible to delete it at any time until it is closed.
You can repeat the export of the data at any time - even when the settlement is closed.
When the settlement is closed, a booking cut is automatically inserted in the time recording (working time account). Changes to the data can then no longer be made.