I use InDesign CS4 for work to layout a color newspaper. At work I use a Mac Mini. When I work from home I'm on a PC or Macbook Pro.
When I pull files over from the server at work I get this error and I didn't think much of it, but now when I try to make a Book, it complains about missing plugins and won't let me ad files.
What is ClassFlow.InDesignPlugin and can I download it somewhere?
I guess that at work you are part of a workflow system, that is using a 3rd-party-plug-in called ClassFlow. So every InDesign document on the server is "infected" with that plug-in.
You may be able to clean your CS4 document from that at home, if you open the InDesign document, export to IDML, open the IDML with InDesign and save to a new name.