Just switched from CS3 to CC15, what a mess. In InDesign I can open an old file, modify or simply re save it as a 15 version. Then when I try to re open the file later InDesign crashes. I restart the program and it tries to recover the doc that caused the crash, and the process repeats. If I delete the temp doc that InDesign creates when the file is attempted to open, that helps... the program will launch and then it will tell me the file is corrupt, would I like to open it anyway? If I say yes, it will crash again. So to continue using the program I have to say no, but guess what, the file is now useless, I can see it, but I can't open it. So its basically gone, I've lost that work. I've tried opening back ups that were created before the second attempt to open the file, and the back up file does the same. I've deleted the InDesign prefs, the InDesign Cache for temp files etc. Nothing works, the file is rendered useless no matter what. This is only happening randomly to certain files, some are brand new creations from "open new file", some are re saves from a CS3 file, some have fonts, some don't. Some are on my NAS on my LAN and some are on my drive locally. This is a huge problem as I am a deadline oriented publisher. To hit my first deadline with all new Mac Pros and all new CC software I had to have everyone keep all the files open that they had created for 2 days until finals were complete and we could create our PDFs. That meant none of us could share files. If anyone closed a file they would risk losing it for good as it might not re open. On top of all this random pages that we create will not print anymore, they are no different than any page we have created over the last 20 years, but all the sudden most pages will not print to my HP Laser Jet. I don't expect to get an answer, but this exactly why I never upgrade until outdated hardware forces me to. Now I have this nightmare to deal with. We are all on Yosemite for what its worth.
Best practice would be to export .inx from CS3, then open that in CC.