I have a mac os 10.4.11 with flash Player Version 10.3.183.75 and can't open Adobe Flash documents.

I have a mac os 10.4.11 with flash Player Version 10.3.183.75 and can't open Adobe Flash documents.  When I try to open a document, it says "A newer version of the software is already installed on this system".  How do I install the correct system that will allow me to open the documents.  The documents are XLS