Epub validation error
I'm getting Epub validation errors
WARNING OEBPS/content.opf 6 24 title element is empty
ERROR OEBPS/content.opf 18 46 character content of element "dc:identifier" invalid; must be a string with length at least 1 (actual length was 0)
Used Indesign CS 5.5 to create.
Any help would be great.