Runtime Error in Xcode When Generating Mesh Data for Mobile AR Build

you can check it out here on UDN, https://udn.unrealengine.com/s/question/0D54z00008PS4rGCAT/invalid-mesh-data-from-tracked-geo

you need to modify the AppleARKitMeshData.cpp file

look for lines
line 180 InVertices.stride == sizeof(FVector) &&
and
line 229 InNormals.stride == sizeof(FVector) &&

replace those with:

line 180 InVertices.stride == sizeof(FVector3f) &&
and
line 229 InNormals.stride == sizeof(FVector3f) &&