If there are no native features found when a DGN is opened, OpenCities Map will look at the first element on each level and set the feature class type to match that element . For example, if there is a line and a polygon on a level called Schools, and the line was the first element placed, the feature class is set to line. If the feature class is incorrect for non-native features, you may need to analyze the level and ensure that all elements are of the same type.