check the form name field in the report form where the report in question is stored. I get this error in ITSM 7.1 when the form name is not set to the form that the report was created to run against. IE: form name field has HPD:Helpdesk and report was created to run with HPD:HelpDeskPeopleReportJoin
Please check if there are fields in the Crystal Report that do not have access to the user (you are using via User Tool).
Check the record for this report in "Report" form to find for anything missing there ,also check whether you have properly configured the User DSN on Server with Proper Credentials.
And On Remedy User (Tools->Options), defined valid report server, and mark “ODBC Use Underscores” checkbox.