Cheryl, 2 things. First, a fix, I think, for your scripts issue; then, a better solution that came out since I recorded the video.
The fix: Make sure you’re putting the scripts into an epub folder in your Applications folder. They should be in the path specified in the alert message: ?/Applications/Adobe InDesign Cs5.5/Scripts/Scripts Panel/epub/extractpages.jsx?”
Do not put them into the same-named Scripts/Scripts Panel folder in your User folder, as Bob suggest. (Normally a good solution Bob!)
The better solution: If that still doesn’t work, then I urge you to ignore all that and just use Rorohiko’s free “ePubCrawler” script.
https://www.rorohiko.com/wordpress/manuals/fixed-layout-epub-assistant-in-indesign-epubcrawler/
They wrote the CSSGeometry.jsx one I showed in the lynda.com video. After it went live, I continued working with them, and ePubCrawler is the latest evolution of that script.
It’s essentially a “make fixed layout epub” solution from any InDesign file. It’s what I use now. When I get the opportunity to update that video, I’ll be scuttling mention of all those workarounds for ID files and instead I’ll show ePubCrawler as well as a couple new commercial plug-ins (Flipick and CircularFlo for now).
I reviewed ePubCrawler and showed before/after of a sample kid’s book in an issue of InDesign Magazine last fall.
Hope that helps!
AM