Microsoft Word on my MBP is not working after Yosemite update. Please help.

Hi all!

I just got the Yosemite update and realized that I cannot use my Microsoft Word (I believe I have the 2009 version). I cannot write/create documents. I can only read, and copy and paste. How can i address this? Are there software updates for the MS Office that will allow it to be compatible with the Yosemite update? Or do I have to purchase a later version of MS Office?