looking at the SDK, I´ve seen this: (about AutogenDescriptions_mid.xml / AutogenDescriptions_min.xml) "Yes. If new groupings or models are added, then they should be referenced in all three descriptions files, otherwise gaps could appear in the scenery during certain seasons, or might occur depending on which descriptions file the user has specified in the configuration file. " So, It seems necessary to add the new class in all those files (AutogenDescriptions.xml/ / AutogenDescriptions_mid.xml / AutogenDescriptions_min.xml). "I have a bad felling about this". This method will bring all kind of problems when several addons begin to modify them. BTW, what is the difference between these files?. I´m checking them (the SDK´s xml version) right now and to me they are almost equal.