During a file-access or disk-access operation, for example, Open, MkDir, ChDir, or RmDir, the operating system couldn't make a connection between the path and the file name. This error has the following causes and solutions:
A file name can contain a fully qualified (absolute) or relative path. A fully qualified path starts with the drive name (if the path is on another drive) and lists the explicit path from the root to the file. Any path that isn't fully qualified is relative to the current drive and directory.
Change the read-only attribute of the target file or save the file with a different file name.
Open the file in Input mode or change the read-only attribute of the file.
You can't make design changes to the project.
For additional information, select the item in question and press F1 (in Windows) or HELP (on the Macintosh).