Propagation of non-existence

If a property doesn’t exist, any other derivatives of that property also don’t exist:

Q: exists folder "z:/foo"
A: False
Q: files of folder "z:/foo"
E: Singular expression refers to nonexistent object.
Q: line 1 of files of folder "z:/foo"
E: Singular expression refers to nonexistent object.

Since the original folder doesn’t exist, any references to the folder are also nonexistent.