I'm sorry to say this but Yosemite and CS4 are incompatable. You're now five versions behind the current on InDesign, and CS4 was never tested with Yosemite.
You should seriously consider upgrading to either CS6 (perpetual license) or get a Creative Cloud subscription for your business.
There's a small chance CS4 will run, IF you did a clean install from the original installer. Migration does not work, and as Steve points out CS4 is not supported on Yosemite, so you're pretty much on your own getting it to run.
thanks. I did install it properly, no migration, and it worked for about 5 weeks until today. Just printing didnt work from the beginning. Today in the middle of working it started. But I see I have bad choices.
ok, its running again! I did it like back in the old days, delete preferences with cmd alt ctrl shift and now its ok again (so far).
Sorry, should have tried that before.