Importing InDesign IDML results in blank chapter

I'm trying to import content into iBooks Author from InDesign. Apple's documentation says to export the InDesign document as an IDML file, then in iBooks Author go to Insert > Insert Chapter From... > InDesign File(IDML). However, when I try this, the imported chapter is blank, containing none of the content from InDesign, only a generic chapter heading. I think I'm following the instructions. I'm using the latest versions of both programs—InDesign CC 2014 and iBooks Author 2.2 running on Yosemite. Any help would be appreciated. Thanks.