From Xojo Documentation
| This property has been deprecated since version 2019r1 and should no longer be used.
Please use FolderItem.OpenAsMovie as a replacement.
| This method is only available on the macOS platform.
For cross-platform development, use ＃If...＃Endif with the Target... specifiers to make sure you will not attempt to use this method on an incompatible platform.
Opens the movie specified by ResID as a movie (Macintosh only).
Used only if the movie is stored as a MooV resource. Use OpenAsMovie for QT 4.0 (and greater) files.
The following code accesses the resource movie numbered 1. The video/mp4 file type has been added to the project by the File Types Editor.