名前に空白が含まれているため、WebView はローカルの .htm ファイルを表示できません。エラーが発生しています
Error Domain=NSURLErrorDomain Code=-1100 "The requested URL was not found on this server." UserInfo=0x400ea1900 {NSUnderlyingError=0x400265c80 "The requested URL was not found on this server.", NSErrorFailingURLStringKey=file:///Users/olgadalton/Library/Caches/ee.64.xxx/_books/Deployment-guide-for-Microsoft-SharePoint-Server-2010_2/OEBPS/Text/Deployment%2520Guide%2520for%2520Microsoft%2520SharePoint%2520Server%25202010_split_000.htm, NSErrorFailingURLKey=file:///Users/olgadalton/Library/Caches/ee.64.xxx/_books/Deployment-guide-for-Microsoft-SharePoint-Server-2010_2/OEBPS/Text/Deployment%2520Guide%2520for%2520Microsoft%2520SharePoint%2520Server%25202010_split_000.htm, NSLocalizedDescription=The requested URL was not found on this server.}
ただし、ファイルはファインダーと端末リストとともに存在します。
ls -l
total 6024
-rw-rw-r--@ 1 olgadalton staff 3925 Oct 11 2011 Deployment Guide for Microsoft SharePoint Server 2010_split_000.htm
許可もOKです。