I am getting the error: character content of element "dc:identifier" invalid; must be a string with length at least 1. Sounds like the fix is to open the source code and place the ISB number into the dc: identifier. Can someone post what code and am looking for to add this to? May sound trivial but I am new with code.
Also, the validator is telling me to take the spaces out of my file names. I can't do this since the TOC uses these names. Is this going to be a problem in final validation?