Some history, please...
Was it working before on this computer? What changed just before it stopped? What OS?
I'm using InDesign 6 now, so indeed, this is the first time i'm trying to open 4 on this Mac.
It's a iMac with OS X 10.9.5
How did you install it? Migration doesn’t work and even if you installed it properly, CS4 is unsupported under Mavericks.