And with book files -
I'd be inclined to export the book files to IDML
Open each in InDesign - resave them
Build a new book file using InDesign CC2014.
This script comes in handy http://www.kahrel.plus.com/indesign/batch_convert.html
Thanks, Eugene. I tried it on a couple of my files and it seemed to do the trick.
Another question that I have. Despite all the new features that Adobe has introduced, I cannot seem to find the button to bill Adobe for the time I will spend converting all these files so that they finally function as they are supposed to. Any tips would be most welcome
Technically - you should work on ongoing projects in the version it was created in.
For example, I wouldn't switch to CC2014 and work in that if I was working on a project in InDesign CC.
I'd continue to work in CC - until the project is finished. If I need to work on it again at a later date I'd do the IDML dance and open it all in the new version, creating new files for the new version of InDesign.
That being said, the IDML route is a way of removing corruption/excess data from files and debloats them. It could simply be that one or more than one of your files had excess code build up - that could have been slowing down InDesign - or in fact confusing InDesign CC 2014 as it didn't know how to handle said code.
The IDML route is always preferred when moving from one version of InDesign to another, whether that's going back a version or forward a version.
Especially with Book files, I always recommend to start a new book file and convert the old files before importing them to the new book file.
This is basically because each version of InDesign is slightly different - see here for a better explanation - http://in-tools.com/article/whats-with-back-save-to-earlier-versions-of-indesign/
That explains why you can't open newer files in older versions - but it speaks to how the database changes for Indesign in each version.
Hope that makes sense.