Thanks for your interest Casper

The file acm23test.mw is a Maple  worksheet that reads in a file name acm23.mpl and has the purpose of tesing out the maple program in the mpl file

It was written in Maple 12 which is no longer available, so I tried to open it by single clicking on it and then choosisng open with Maple 16 in the finder.  This gave me the message "File acm23test.mw could not be found.  Please select a different file."

I also tried going to 'get information' and changing the open with option to Maple 16  and  got the same response when I double clicked on it.

However, I am happy to report, that I have now discovered that I can open the file from within Maple 16.  If I weren't such a novice, I should surely have thought of this obvious answer before.  It does seem to me rather odd though that Maple should be unable to find a file that is being clicked on and right under its nose so to speak.

David R