What kind of digital book file—PDF, EPUB, Fixed Format EPUB, Publish Online, other?
Version of InDesign? Operating system?
reflowable epub using CC 2015.3 on windows 10
Moving to InDesign EPUB forum
I found the answer on http://indesignsecrets.com/topic/page-anchor-not-found web site - thank you team!
The issue is with the index, particularly ranges rather than single pages. The second number in the range is not linked and creates a missing page anchor. Once these are removed, the issue goes away.
Thanks Steve, for working on this.