CS5.x is not compatible to Yosemite. It might run but if problems appear you are alone. You should upgrade to CC subscription.
I believe, if you're running 10.10, you need to upgrade to InDesign CS6/CC.
I also had the potential problem:
Needed OSX 10.10.3 for ePub production with the latest InDesign and various Reader software inclusively iBooks on OSX.
But also needed InDesign CS5.5 (CS3, CS4) running as well for some clients still with the older versions.
I decided to install two different start partitions on my MacBook Pro.
One, that is for the old OSX and one that is for the latest OSX.
This worked surprisingly well provided you have enough harddisk space you can partition.
However to switch between the two OSX versions, you need to restart the Mac.
There might be other solutions as well.
But anyone who is upgrading now, should be aware that CS6 is NOT supported with the next OS.
See here the statement to CS6 in one answer from an Adobe Staff member: Re: Just subscribed to InDesign CSS - problem: how can I open old Pagemaker 5 and 6 Files?
That is NOT what Dov said. It was simply a warning that it would happen at some point.
Was this an in place O/S upgrade or a migration to a new computer?
In either case they are recipes for disaster. Only clean installs and proper installations of software should be done.