We are still having issues in 2021 with Logitech webcams like Brio Pro or internal laptop webcams.
Webcams are visible and we can see all the different resolutions as video streams but a video is black and unable to play - media failed to open check output log (nothing sows in output log).
It is not a problem of camera because camera works in one project (4.24) but nothing else, not even new project.
M.