SAP Message PPER3E_ECN020 - The change number sequence (&1 <-> &2) is not unique

Diagnosis At least one change number lies on the cycle. This makes uniquesequencing impossible (change number &v1& <-> change number &v2&, nodeV3, variant v4). Procedure Remove the cycle. To do so, choose Logistic -> Production -> Master Data -> IntegratedProduct Engineering -> Display Cycles.