Unfortunately, your first post is very much lacking in detail so any help is likely to be largely guesswork!
Please read this pinned post and supply as much of the requested information as you can, thank you. You've chosen Movie Studio as your software but we have no idea about which version and edition you have. If it is version 17 or older please also read this pinned post and follow its advice.
In addition to the information @emmrecs requested, if it is Magix Movie Studio 18 or later, or Video Deluxe the rebrand name for Magix Movie Studio:
Is the program installed entirely on the C: drive using the default install settings?
Did you change any of the Folderpath settings? If so which and what to?
Are your projects and source media files on an external disc drive, either USB or a NAS box?
. . . . message `path not found` . . . .
What is the full message, it should be telling you the file path, and file if loading a project and it is not where it is expected to be that it is looking for?