Diagnosis
It is not permitted to simultaneously enter a variant and also activatethe 'Variant control' field.

Procedure
Consider whether you want to enter an explicit variant for the currenttable entry, or whether you want to control the variants using the'Rules f. Determining Variants f. Monthly WS Rule Generation' view(V_T550X). In the first case, you must maintain the 'Variant' field, inthe second, you must activate the 'Variant control' field.