FILE NOT FOUND

Hi, unfortunately I'm not too sure what the issue would be without more information. Could you provide more details if you can? Specifically, it would be helpful to know:

What type of file is it? (e.g. Word document, PDF, image file etc.)
What happens when you try to open the file? Do you receive any error messages? If so, do you have an image?
Have you tried opening the file on a different computer or device?
Have you made any changes to the file recently, or has it been working fine until now?
If it's saying 'file not found', have you checked to make sure that the filepath hasn't changed? If you've got it saved as a browser bookmark, you'll need to update it every time you put the original file in a new place on your computer.