Invoice items aggregated cannot be displayed

What causes this issue?

You attempted to process the items from the aggregation screen. This is
only possible if you have called up aggregation from the batch
comparison overview screen. In this case, however, you called up
aggregation from online Invoice Verification.

System Response

You are not allowed to call up item processing.

How to fix this error?

You can edit the items by exiting the aggregation screen.

Error message extract from SAP system. Copyright SAP SE.