Trouble adding an uncredited credit to Sol Madrid (1968)

@Bethanny I tried to add an uncredited credit to Sol Madrid in contribution #250109-170138-744000 but IMDb rejected it. The uncredited person is Vince De Rosa musician: french horn Here is the photo and reliable link of where I've found it. https://www.filmscoremonthly.com/cds/score.cfm?SCID=103