Enter only one of the following: costing date, period, period indicator

What causes this issue?

You have made an entry for more than one of these fields. However,
these fields are mutually exclusive. Consequently, you can only make an
entry in one.

System Response

The costing key cannot be processed any further.

How to fix this error?

Remove the entries that you do not need.

Procedure for System Administrators

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

Error message extract from SAP system. Copyright SAP SE.