You need to have an Open and Saved InDesign file otherwise ID2Office won't know which document to export. Note that you can open an older InDesign format file in a new version of InDesign and the file is not saved yet. So as an example, you can open an InDesign CS5 file in InDesign CC but it’s not saved as an InDesign CC file. So, it must be a native CC file at that point.