errors were encountered in this item file://users

2 books were marked protected but I downloaded as was available. Unable to open and read as get an error pop up "errors were encountered in this item file://users/Anita/documents/My%20Digital%20Editions/Mechanical%20The.epub". The nice thing about errors is there is no information that I know to use to find a correction or root out the problem. I was able to read unprotected book with no problem. I downloaded Jaws but it look too complicated and seemed to have cost. Any help would be appreciated.