Hello All ~

I have an iMac running OS X, version 10.9.5 with Office for Mac 2011, version 14.4.8.

Recently, I can not open Word or Excel files that come as email attachments.  I get the following error message:

Oddly, when I forward the email to my Macbook Pro running OS X Yosemite, version 10.10.2, I do not have an issue at all. 

I've seen some forum posts on this ~ but nothing with a concrete solution.

Anny suggestions, help, instructions would be greatly appreciated!

Thanks in advance