“Error encountered fetching data” in iNotes

After researching it a bit it appeared that all users were running Windows XP SP2 which really is the clue. When running WinXP SP2 against a Domino 6.5.1 (or previous) server you may get this error since service pack 2 replaces a data access component used by iNotes.

The fix is either to upgrade the server to 6.5.2 or later or to toggling the “Character set in header” setting on the server document (under “Internet Protocols””Domino Web Engine”) to “Disabled”.

There is a technote on the subject here.