To be able to open an Adobe InDesign CC file in CS3 there is two simple steps:
- Open the InDesign CC file in CC and export the file as an IDML (InDesign Markup Language) file, using the Export options from the File menu or the Save As option.
- Then in CS4 open this IDML file and export it to an .inx file. This file will now open up in InDesign CS3.
If you don’t have Adobe InDesign CC, or InDesign CS4 we offer a InDesign down-saving service to help open the file into the CS version you need.