QuickTime Player 7 supports older media formats, such as QTVR, interactive QuickTime movies, and MIDI files. It also accepts QuickTime 7 Pro registration codes, which turn on QuickTime Pro functions.

This version of QuickTime Player is unsupported and is provided for compatibility with legacy media workflows on macOS Sierra and earlier. QuickTime Player 7 isn’t compatible with versions of macOS released after macOS Mojave.

Learn how to use the latest version of QuickTime Player (version 10) included with macOS here: http://support.apple.com/kb/HT201066.