EF2 happens when the file in the path does not exist.
e.g. Opening a file for reading that does not exist.

EF5 is essentially the same as EF2, but something in the middle of the path does not exist.
e.g. /DIR1/BADDIR/LOG/FILE.TXT - where BADDIR does not exist.

EE7 occurs when you open a file, but the path specifies a directory.