Cost estimate saved temporarily

What causes this issue?

The cost estimate for the reference object (order, WBS element, etc.)
was saved locally but was not written to the data base.

System Response

The system issues an error message and will not allow you to continue with this transaction until the error is resolved.

How to fix this error?

Before leaving the master data, you have to save the base planning
object again.
Before leaving the planning function, you must save the planning data
for the order or WBS element again.

Error message extract from SAP system. Copyright SAP SE.