org-open-non-existing-files

org-open-non-existing-files is a variable defined in `org.el'.
Its value is

nil

Documentation:
Non-nil means `org-open-file' will open non-existing files.
When nil, an error will be generated.
This variable applies only to external applications because they
might choke on non-existing files. If the link is to a file that
will be opened in Emacs, the variable is ignored.

You can customize this variable.