Q: Update Acrobat 9 Pro in Yosemite

click the link to the Adobe FTP site, and select connect as guest:     Acrobat Pro 9 updates

you will need to install each incremental update in order, the last version was 9.5.5

Simplest thing to do here is uninstall Acrobat using the Adobe uninstaller application, then re-install using the original instal file then update to the next version until it is completely uptodate.

Thanks so much Gary! 

I only had to install one update, then it opened, and did the auto install updates the rest of the way to 9.5.5 and all is working.

Hello Gary,

Thank you for your post and direction, you fixed my problem.

Thank you, Gary! You are awesome. I can't tell you how many hours I spent installing/uninstalling and reading other posts about how to get Acrobat Pro 9 to work in Yosemite. I am using CS4, installed the first level incremental update from the ftp site you posted and boom, I was finally able to get into Acrobat without a hitch!