the attribute's value is not added in item using ItemMatrix api
i am trying to add attribute's value in item using ItemMatrix api. the attributes are color and size . and the values are balck,blue/s,m. but its gave me an error.
the error is:
"httpMessage": "Internal Server Error",
"message": "An error has occurred and we've been notified. Please try again and if this problem continues please contact support.",