Hotel Reserve is a 1944 spy film starring James Mason as an innocent man caught up in pre-Second World War espionage. It was based on Eric Ambler's novel "Epitaph for a Spy". Unusually, it was both directed and produced by a trio: Lance Comfort, Mutz Greenbaum (credited as Max Greene) and Victor Hanbury.
James Mason died in 1944.
We don't know when he died because it's never mentioned. It's possible he acted in the film in 1944 and still died later that year. It's difficult because the system probably assumes he must have been alive throughout all of 1944 if he acted in 1944.