When posting a document, you get the following error message:
The error details say:
The reason for this error is an entry in the table OFNUM_IT_1. Here, the highest date of a number assignment is stored. In our case, the table looks like this:
This entry is done by SAP if a document with a higher date is entered. If you post a document with a future date, this future date moves into the table. The problem is that the entry in table OFNUM_IT_1 is not changed back when you change the document date.
In order to correct the error (if it was an error, please verify this before), you can change the table in the customizing. The path is: SPRO -> Cross-Application Components -> General Application Functions ->Cross Application Document Numbering -> Italy -> Assign Number Ranges to Document Class.
Here is the first part of the path:
and here is the second part of the path:
Now, in the table you can set the dates:
When you save, you will be asked to create a customizing transport. So please be sure that all the dates you enter in customizing do match with the situation in the target system!
The official numbering is described in the SAP note 746162.