This looks like a VB Winforms app?? What type of files are in the Reports folder?
Did this suddenly happen or did something change in the system? If so then what?
It is possible the files were removed from the solution so go to the Show All Files option in the toolbar at the top of Solution Explorer and show all the files. Then right click each file that is missing and select the option to include in the project. Then you can disable showing all files.