Diagnosis
In the interface format, you have specified the import of "All entriesin the current period" (table) or "All records valid on at least oneday in the current period" or "All existing records, also outside thecurrent period" (infotype). If there are several entries in the table,the "Delimit" function cannot work properly without the key fieldsbeing defined.

Procedure
In principle, you should define key fields for tables or infotypes inthe validation check to make it possible to clearly assign table linesin the current and previous period.