Service entry sheet & is not yet approved

What causes this issue?

You specified materials and selected the field "Pool valuation".

System Response

The system will ignore your material entries if you confirm the message.

How to fix this error?

If you want to form a base layer for pool valuation, confirm the message
by pressing ENTER.
If you want to form a base layer for the specified materials, deselect
the field "Pool valuation".

Error message extract from SAP system. Copyright SAP SE.