If the Toshiba Video Player plays a major role in your daily life, then I recommend downgrading Windows 10. You can do this using Start > Settings > Backup and Security > Windows Update > Get Back. This option will rollback the updates, thus restoring the functionality of the video player.
You can then wait until a new update is released for Toshiba Video Player that is compatible with Windows 10 or use another video player to play your DVDs. For example, VLC Media Player handles DVDs very well and supports loading all kind of formats.
