HEVC (H.265) requires hardware or software decoding:

The mention of "install" in your query suggests you may be seeing this on a site that asks you to download an file to "view" or "install" the movie. ⚠️ Security Warning : Standard video files (like do not require installation

: "Installers" for movie files are often masks for malware or unwanted software. Legitimate video files (like .mp4 or .mkv) do not require an installation process.