Ok, after using the above fix, I was able to access Apsona, and get as far as importing (a portion) of my product file. Of 2500+, after "Importing" only 900 (always 900), I get
The server is not responding. Please check your network connection.
Status: error
. Then, if I cancel the upload, and try again, I get
System progress bar unavailable: Maybe some other component is using it?
I've tried reading through the thread but haven't found (not yet at least) a reason or solution for this.

Delia, do you know anything about why this may be happening, or a possible fix?