Please specify the application you are using.
Hello! I'm using Lightroom
Lightroom is suddenly telling me files cannot be found.
The message that you see " Files cannot be found" is because the file have been moved from their actual location of import.
So in order to edit them, I would suggest you to reconnect the files.
Please refer to the following article : https://helpx.adobe.com/lightroom/help/locate-missing-photos.html
Please let us know if it helps.