SAP Note 19465 - Drill-down reporting: Line structure contains error

Symptom:

Drill-down reporting: only COPA
WHen execute a report, you receive error message KH207:
Rep. line structure & contains errors -> Check.

Cause and prerequisites

Possible cause: The line structure formula refers to elements of the line structure that do no longer exist.

Solution
Correct line structure formula via transaction KER1 - Formula editor. First you have to determine the incorrect formula via transaction SE16 for table T237. There, you have to make sure that all elements of the line structure which are used in the formulas (especially the 9000s entries) are actually available.