The problem is that you are trying to read the file from the disk, using the data in your resources as the path to the file.
It doesn't
"Assign( Properties.Resources.File) to picArray" it tries to use that info as as file path instead. Probably, you want this instead:
byte[] picArray = (byte[])Properties.Resources.File;
System.IO.File.WriteAllBytes(@"Path", picArray);