When i try starting a session it says it found disallowed object type, any ideas?

i got the error: LogValkyrieValidation: Error: [16] Found disallowed object type /Game/Balance/Physics/Materials/PhysData_Foliage.PhysData_Foliage when trying to start a sesion
so i tried to look in the outliner and i to maybe find it but i didnt can somebody pls help or just give some tips on how to get rid of it