You may not enter values for item no. & (totals item)

What causes this issue?

You try to post to a <GL:line_item>line item,</> which by
definition is indicated as a total item

System Response

Total items may neither be entered nor posted.

How to fix this error?

Choose either a <GL:value_item>value item</> or check the
definitions in the item catalog.

Error message extract from SAP system. Copyright SAP SE.