clsid2

Yes There are just two compatible renderers at this moment: MPC Video Renderer Jriver Video Renderer

It does two switches in this situation, one for the fullscreen mode and one for turning on HDR mode. Looks like the HDR switch is attempted while the fullscreen mode...

There already is a delay option in the fullscreen settings page that can be used to solve the problem.

Mediainfo issue is already fixed. If you are insinuating that MPC-HC is buggy, then you are just confirming your stupidity. Mouse pointer is hidden intentionally in fullscreen if you don't...

You can't hurt me. I am not having problems. Try MPCVR build from MPC-HC download page. That does not block WM_NCACTIVATE window message like standard MPCVR does. Maybe that helps.

https://github.com/clsid2/mpc-hc/releases/download/2.1.2/mpcvr_0.7.0.2148.zip

When this happens to me, one of the Firefox processes is hanging. So when restarting Firefox, it complains it is already running, allowing me to terminate the previous instance.

@nevcairiel Any plans for official support for LanguageIETF in LAV Filters? It was added in MkvToolNix v50.

matroskadec_haali has never been part of FFmpeg

Try 2.2.1.48