When saving my Adobe CS6 InDesign document, why does it save as an Adobe Illustrator document?

Question

When I click "Save As" it looks as if it will save it as an indd document, but in fact it saves as an AI document.  However, when I double click the icon, it tries to open in Illustrator, but then I get an error message stating it cannot open the document.

Answer 1

It means that your file associations in Windows are messed up - all .indd files are assigned to open up in Illustrator. Shutdown InDesign, open up any file that you know is an InDesign file, right-click and select Properties, and it'll say "Opens With: Illustrator." Click on the CHange button, then choose InDesign from the window, and make sure that the "Always Open With" box at the bottom is checked.
That's how it's supposed to work, anyways, When file associations are messed up in Windows sometimes it takes a lot more work to fix it. But give that a shot first.