Looks like the document is opened in the newer version of the Indesign.
Open it up in CS5.5 or CS6 , save it as IDML and then open it up in InDesign CS4
My guess is it's a CS6 file since it mentions form fields in the list, but you can use Jongware's tool to find out: Adobe Forums: [Ann] Identify Your InDesign File
Your OS cannot identify a file as anything newer than the most recent version you've installed, which leads to a lot of confusion, and no, newer versions are not backward compatible -- never have been in ID. To move files back to earlier versions they must be exported as interchange format files from the version where they were saved. Since CS4 that has been .idml, and all versions of ID since CS4 can read .idml exported from any version, but unsupported features from newer documetns will be lost and text will probably reflow, so you shouldn't have any expectations of a perfect conversion.