Imdb won't let me add credit for an archival sound of a dead actor. How to solve ?

I am trying to add a credit for an archival sound I used from an actor who is dead now. IMDb keeps declining the entry due to Badly formatted error. I have included screenshots end credits from my film and a film festival page that mentions the use of the voice of that actor. I have also added statements saying from which film the sound was taken with permission of the producer. But I still get declined. Kindly help  !