Aleph One 1.7.1 cannot open Aleph One Map Files through right clicking and opening or with drag and drop on Mac OS

[spencerthayes]

When attempting to open a map file by right clicking and opening with Aleph One or the standalone version of Marathon Infinity (I haven't tried with Marathon 2) I am presented with the following error:

The same error is given when the file is dragged on top of the application icon.

This error does not occur with the same file on Aleph One version 1.5 and instead opens normally.