Diagnosis
You want to enter a class item in a BOM. The selected components areallocated to this class.
Either the object numbers of the selected components is the same as theobject number of the object represented by the BOM, or the selectedcomponents contain an item with this object number when exploded. Forthis reason, the BOM is recursive.

Procedure
If you want to enter this class as an item, you have to set theindicator in the Recursiveness allowed field.