If any field being exported contains more than 32767 characters then:

• The export will fail
• A white “Report” dialog box will be displayed, showing only the text “There was an error generating this report.  Please contact your system administrator” at the bottom
• No errors are logged to the Service, WebService or WebUI log files

 The only workarounds are to either exclude this record from the export via a filter, or to remove the long text entry.  This number of characters is equivalent to about eight pages of text (11pt), so it is likely better stored in a file attachment in any case.