For the reproduction of video files in MB STUDIO, the correct installation and configuration of the LAV video codec is required.
Download the codecs in the standard package from this page: https://codecguide.com/download_k-lite_codec_pack_standard.htm
Proceed with the installation taking care to DECLINE the installation of an additional adware software that does not interest us:
At the end, execute "Codec Tweak Tool"
Click on Win7DSFilterTweaker: Preferred decoders
Set all available options on LAV Video
and click on Apply & Close.
In windows, enable the display of all notification icons:
This is necessary because you have to check that while MB STUDIO plays a video file, in the taskbar there is the red LAV VIDEO icon that indicates that MB STUDIO is using the right LAV codec
If the red LAV VIDEO icon is not present, this means that MB STUDIO is not using the expected codecs and may experience black video or completely out of sync or other malfunctions.