Diagnosis
The date you have entered (&v1&) is within the validity period of thevalid-from assignment &v2&. This assignment has been used already forthe settlement period "to &v3&". The relevant rental unit assignmentsmust not be changed so that this settlement can be analyzed again at alater date.

Procedure
Please enter a date that does not affect the assignment used in thesettlement, that is, one that is after the end of the settlementperiod.