SAP Message C0661 - Invalid use of characteristic in function call (charact. no. &)

Diagnosis
In the selected function call, an import parameter or a changingparameter has been defined as a constant (characteristic no. &V1&).However, import parameters and changing parameters can only betransferred to a variable.
INCLUDE 'NA_FU_NO' OBJECT DOKU ID TX LANGUAGE E

Procedure
INCLUDE 'NA_HA_TST' OBJECT DOKU ID TX LANGUAGE E
RESET N1
INCLUDE 'NA_HA_POS' OBJECT DOKU ID TX LANGUAGE E
In the process order, correct the definition of the parameter(characteristic no. &V1&) in this process instruction.
INCLUDE 'NA_STREZ_NEU' OBJECT DOKU ID TX LANGUAGE E
Change process order
INCLUDE 'NA_HA_PROD' OBJECT DOKU ID TX LANGUAGE E
Errors in the process instruction cannot be corrected for the currentPI sheet.
INCLUDE 'NA_PLNREZ_HINW' OBJECT DOKU ID TX LANGUAGE E
Change master recipe