PDf viewing problems with macs

I am pretty knowledgeable with Pc's but not with macs.

I am using a 3rd party app that generates a pdf file. On all PC's the pdf looks perfect.

However, on all macs tried so far the pdf opens and displays a mix of letters that is similar to machine code, but not exactly.

These macs have a mix of differrent OS and diff versions of pdf reader. Nothing seems to matter.

All fonts in the pdf are embedded. No search indicates this is a typical problem.

Can you help. You can view one of these pdf files at hawthorneacadpta.org

Thanks
Eric