Will not open WP files created with WP 3.5 for the macintosh

I just flushed $10 completely down the potty. This application is worthless to me since it will not open WordPerfect files created with WP 3.5 for the mac. I still have an old mac with WP 3.5 that ran under System 9, but was hoping to work with these WP files on my modern OS 10 mac.
It is unfortunate that you cannot try these applications on your files before wasting hard-earned money on them. At least the developers should state the limits of the application and for a translating program such as this one, what it cannot not do.

rlwnsf about WordPerfect Document Viewer