You're not "converting a string". You're building a path to a file, and I don't think you're doing it correctly. You're path is jumping up 4 directory levels, then going down one into a " Restaurant_Application" directory (note the space on the beginning of the name) to find the file. Your code is assuming that's where the file will always be relative to the "current directory". Never use .. in path names to jump between folders. The "current directory" may change and your code will not know to change that path. ALWAYS build a path to a file based on a well-known root path.
Look into
Environment.GetFolderPath[
^] and
Environment.SpecialFolder Enum[
^] to get the well-known path to start with. You can then use Path.Combine to append folders to that path to build the path to the file you want to get at.
Oh, and why are you putting a bunch of spaces in the path? Remove them. Yes, they matter and CAN impact the validity of the path you build.