Error with assignment for program item &1 / &2 / &3

What causes this issue?

Program position:
The program position &1 / &2 / &3 is not assigned for the automatic
derivation of characteristics.

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?

If you want to know the detailed error message(s), assign the program
position manually, or assign a valid program position.

Error message extract from SAP system. Copyright SAP SE.