1.12.2 - browser - fullscreen - video not played (black screen, play bar disabled) - regression of #3663?

[karlheiners]

When a video is opened in fullscreen directly from the browser, it never plays: the screen stays black and the play bar buttons are greyed out.
This looks like the same problem as 1.9.1 - browser - fullscreen - video file not shown (Mantis #3663, fixed in 1.9.2).

Steps to reproduce

1. Settings > Interface > Switching modes > Double-click: Browser <> Fullscreen
2. In the browser, double-click the thumbnail of an MP4 (H.264) video

Result: Fullscreen opens, black screen, play bar disabled, the video can't be started.
Expected: The video plays (or can be started with Play).

What works

• Same file with Double-click set to Browser > Viewer > Fullscreen: the viewer opens and Play works.
• Switching from the viewer to fullscreen (double-click or Enter) keeps playing.

So only the direct browser -> fullscreen path is broken.

Notes

• Happens every time, with my own MP4 files and with a small 640x360 H.264 test file, also right after restarting XnView.
• full2Monitor on/off: no difference.
• With Qt multimedia logging enabled, Create PlaybackEngine is logged when the video is opened in the viewer, but never when it is opened directly in fullscreen from the browser. So the player doesn't seem to be created on that path.

My xnview.ini and the test file are attached.

[cday]

My xnview.ini and the test file are attached.

I don't see them, probably best to put then in a ZIP (2MB max per attachment) or to provide a download link.