I am getting this error when I get a rescheduled invititation for a meeting. I try to open the document then I get the same error then it opens.Notes 6.5.1 and mail mail6.ntf and inotes6.ntf all the same no change.
Subject: Repeating instance document corresponding to this notice cannot be located
It sounds like you deleted a calendar document that contains the “repeating calendar information”. This probably isn’t a bug with the mail template/design, although the error message isn’t very helpful. Compact/fixup would make no difference. There’s nothing wrong with the database file. I think your only option is to reschedule the meeting.