The reference/target combination is not possible

What causes this issue?

You want to copy &V1& and have not entered a valid combination for the
target copy entry.

System Response

You can only copy the planning if you enter the correct combinations
for the reference and target objects.

How to fix this error?

Correct your entries. The following is a list of the possible
combinations for copying the planning:
all objects -> according to reference
one object -> according to reference
one object -> different object
one object -> object group
object group -> according to reference

Error message extract from SAP system. Copyright SAP SE.