ShotGrid Create black screen for video playback

Hello,

We have installed ShotGrid create and ShotGrid RV on our Fedora 34 system, but are having troubles with video playback.

When a video is opened, there is no playback, only a black image. If we click the “Play in RV” button, then the video plays fine in RV.

When ShotGrid Create is first opening, we get this message in the console:

[ PLAYER ] No display found

When the video is loaded we get this error:

ERROR: Open of '/users/.../.cache/Autodesk/ShotGrid Create/shotgun_library_cache/download/.../filename.mp4' (Original URL : 'sgc:///file_serve/version/7122/mp4?804') failed: unsupported media type.

We have verified that this is a valid file by opening it with

ffplay ~/.cache/Autodesk/ShotGridCreate/.../filename.mp4

What can we do to get playback working in the ShotGridCreate window?

Thanks for the help.