Just purchased Movie Studio 2023 Platinum and the web cam video I recorded resulted in a *.mxv format. While trying to playback and add the video to a project I got an error message stating this type of format cannot be read.
The .mxv file format is a custom Magix video format so imports natively ie you do not need any external codecs installing, however depending on where you saved the video file, and the version of Windows and Antivirus you are using, access may be blocked due to protected folder.
The video file should have been loaded automatically onto the timeline - was this when you got the error message?
Where did you save to video to?
If the video is not in the default folder location, ie in Documents, Magix Projects, My Record, or at least within the Documents folder,then try moving the video file to this folder and load it into a project.
If the video is in the My record folder, try temporarily turning off the Folder/Ransomware/Real time protection feature of you Antivirus program and test if it will load into a project.