My CS5 InDesign program will not open on OS Sierra 10.12.1

[Guest]

I recently updated my MacBook Pro to OS Sierra 10.12.1 and I am unable to open InDesign, however, the other programs in my Adobe CS5 Suite open just fine.  I am receiving the notification below, can anyone assist with how I can get this app repaired/opened?  Thanks!

[BobLevine]

CS5 is completely unsupported under Sierra. Roll the computer back to your earlier operating system.

[Guest]

Thanks BobLevine!  What is the best way to roll the computer back to the earlier OS?

[BobLevine]

Without a backup, honestly, I don't know.

I'm more of a Windows guy but what O/S were you using before you moved to Sierra.