I don't have a link (I'm on Windows, not Mac) but I have seen it mentioned that an OLD version of Java must be installed to get an old program (CS6 and earlier) working with your new operating system
Otherwise, Owners of old programs simply have problems with Mac El Capitan/Sierra... none of which is Adobe's fault... Adobe did not change your old program to make it stop working... Apple changed their operating system and THAT is why your old programs won't work, not because of anything Adobe did... Also... every time Apple issues an update, there is the risk that an old program that HAS been working will STOP working... bottom line, old programs require a matching old operating system
You did not say that your problems began when you upgraded to Sierra (on which CS5 is not supported) so in the case that you were previously somehow able to use InDesign on Sierra but it is not working now it might be a good idea to reset your preferences.
To do so:
With InDesign closed Launch a Finder Window in column view and click on your home folder. With the Option Key pressed choose Library from the Finder Go Menu. Within the Library folder find the folder called Preferences and within it find the following two files and delete them: “Adobe InDesign” and “com.adobe.InDesign.plist”. When InDesign is next launched it will create new preference files and the program will be restored to its defaults.
After you’ve reset up the program (make sure that no document window is open) to your liking, it is a really good idea to create copies of your personalized “mint” preference files (make sure that you quit the program before copying them—that finalizes your customization) and use them in the future to replace any corrupt versions you may need to delete.
Many thanks! You're probably right but going back to an older operation system is not what I intended to do, it would be really just the last option if nothing else works. For now I'm going to try to deinstall and then reinstall InDesign and am hoping that this will solve the issue.
Thanks to you as well! I have tried that but unfortuantely it didn't work. Same probelm appeared. Thanks anyway. I'm going to try to reinstall InDesign and see if this helps.