PROBLEM SOLVED!
It seems like Object Properties -> User Defined Properties had some Vray data in them and it prevented them to export (or sneak peek).
VRay_MoBlur_GeomSamples = 2
VRay_GI_Generate = True
VRay_GI_Receive = True
VRay_GI_Multipier = 1,000000
VRay_GI_GenerateMultipier = 1,000000
VRay_GI_SubdivsMultiplier = 1,000000
VRay_Caustics_Generate = True
VRay_Caustics_Receive = True
VRay_Caustics_Multipier = 1,000000
VRay_MoBlur_DefaultGeomSamples = True
VRay_Matte_Enable = False
VRay_Matte_Alpha = 1,000000
VRay_Matte_Shadows = False
VRay_Matte_ShadowAlpha = False
VRay_Matte_ShadowColor = [0,0,0]
VRay_Matte_ShadowBrightness = 1,000000
VRay_Matte_ReflectionAmount = 1,000000
VRay_Matte_RefractionAmount = 1,000000
VRay_Matte_GIAmount = 1,000000
VRay_Matte_GI_OtherMattes = True
VRay_GI_SurfaceID = 0
VRay_SSS_SurfaceID = 0
VRay_GI_VisibleToGI = True
VRay_GI_VisibleToReflections = True
VRay_GI_VisibleToRefractions = True
VRay_Secondary_Matte_Enable = False
VRay_MoBlur_Override = False
VRay_MoBlur_Override_Duration = 1,000000
VRay_MoBlur_Velocity_Override = False
VRay_MoBlur_Velocity_Channel = 1
VRay_MoBlur_Velocity_Multiplier = 1,000000
VRay_Generate_Render_Elements = True
Ignore_In_VRayRT = False
VRay_Has_Toon_Outlines = True