Why does Articulate Presenter remove my PPTA files and append -old?

Greetings Articulate Support,

Please excuse my brevity, this issue has taken too much time already:

1) I open a PPT file that was created in August of 2014, using whichever version of Presenter was most recent at that time.  I am currently using: 5 1412.920, working locally on my desktop.

2) As soon as I attempt to do work in Articulate, it creates a new empty PPTA file next to my PPTX, and renames my working PPTA file to "[filename]-old.ppa", thereby removing my audio, animations...everything.

3) There is no way for me to retrieve assets from my old PPTA file without setting up a virtual machine, installing the old version of Articulate and republishing.

As a side note, I'm attempting to republish this lecture so that it can be presented at a conference on eLearning/pedagogy next week.  If I'm unable to fix this problem by then, I'll need to explain to the audience why this is the case...

What are my options other than a VM and an old version of Articulate?

-Greg