Convert your video into an Image Sequence (e.g., JPEG or PNG).
By default, Maya often only supports .avi (Windows) or .mov (Mac) for playblasts. How to Get an MP4: Maya.mp4
Use a tool like FFmpeg or Shutter Encoder to export your MP4 as a series of images. Convert your video into an Image Sequence (e
Before working with heavy video files, ensure Autosave is enabled under Windows > Settings/Preferences > Preferences > Files/Projects to prevent data loss if a codec causes a crash. Before working with heavy video files, ensure Autosave
If your video won't load, it is likely a missing system-level codec rather than a Maya bug.
If you need to import an MP4 into Maya to use as a background for tracing movements:
Many professionals playblast to a high-quality .avi or .webm format and then use Clipchamp or Handbrake to convert it to a standard H.264 MP4 for sharing.