Error calling ASO_QUOTE_PUB.Create_Quote_Line from a custom package

 I got the following error when i call the procedure ASO_QUOTE_PUB.Create_Quote_Line:
v_org_id :43
v_price_list_id :18789
INVENTORY_ITEM_ID :1640831
v_party_rec.PARTY_ID :22295
v_party_rec.PARTY_SITE_ID :55517
UOM_CODE :NR
no. of FND messages :2
Error msg: Errore restituito in ASO_QUOTE_LINES_PVT.Create_Quote_Lines.
Error msg: ORA-06502: PL/SQL: numeric or value error: character to number conversion error
U
2
ORA-06502: PL/SQL: numeric or value error: character to number conversion error

Here is mine procedure:

  PROCEDURE ADD_MODEL_TO_QUOTE(i_user_id NUMBER, i_quote_header_id IN NUMBER, i_model_code IN VARCHAR2, o_err_code OUT NOCOPY VARCHAR2) AS