Great Britain trailed in a disappointing last at the Speedway World Cup final in Leszno on Saturday.
Hosts Poland retained their crown, lifting the Ove Fundin Trophy – named after the one-time Norwich Stars legend – for a record eighth time.
The Poles finished on 50 points, seeing off Sweden who claimed silver on 42. Russia matched their best ever World Cup finish, scoring 18 to beat Great Britain (15) to the bronze medal.
King's Lynn Stars Robert Lambert scored one point for the Lions, whose 22-year quest to win a World Cup medal outside of Britain goes on.
Harris, who led the GB scorechart on seven, said: 'Obviously we were good at home, but the riders aren't used to Poland. Out here, it's a different kettle of fish with the equipment, as the boys found out tonight. But it was a great experience for them, though. They'll have learnt a lot for the future.'
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