That mod might conflict with another one, maybe it uses same parts names as some other mod so try removing some mods from the game.
Also Thyago's Golf Mk2 doesn't even let me start BB's SLRR which i've just reinstalled, however it works fine in an old SLRR Stage 1.
!Class not found: java.game.cars.Duhen_models in file "java.game.GameLogic" at line 552
!JVM::getClass: class "java.game.cars.Duhen_models" not found in file "java.game.GameLogic" at line 552
!vm_set_float_field: unknown field: Ljava.game.cars.VW_Golf_MK2;/0
!Class not found: java.game.cars.Duhen_models in file "java.game.GameLogic" at line 552
!JVM::getClass: class "java.game.cars.Duhen_models" not found in file "java.game.GameLogic" at line 552
!Cannot parse class "java.game.cars.Duhen_models" in file "java.game.GameLogic" at line 552
!Class not found: java.game.cars.Duhen_models in file "java.game.GameLogic" at line 552
!JVM::getClass: class "java.game.cars.Duhen_models" not found in file "java.game.GameLogic" at line 552
!Cannot parse class "java.game.cars.Duhen_models" in file "java.game.GameLogic" at line 552
!Class not found: java.game.cars.Duhen_models in file "java.game.cars.VW_Golf_MK2" at line 14
!JVM::getClass: class "java.game.cars.Duhen_models" not found in file "java.game.cars.VW_Golf_MK2" at line 14
!Cannot parse class "java.game.cars.Duhen_models" in file "java.game.cars.VW_Golf_MK2" at line 14
