it's unlikely you'll get InDesign 5.5 (or CS6) to work properly on El Capitan.
As Derek says, you are unfortunately on your own. My only recommendations are to trash preferences and if that fails to work, uninstall, run the cleaner tool and then reinstall.
After that you can either roll back to a supported operating system or move to Creative Cloud.
I've tried reset preferences and succeed! Thanks a lot!