You're not the only one.  It's ALWAYS associated with AJE or AJEE My KSP.log has same errors (66): (Search: Module ModuleEngineConfigs threw during OnLoad: System.NullReferenceException: Object reference not set to an instance of an object) This is the typical section of the log for one of the repeating errors.    [LOG 20:14:15.390] PartLoader: Compiling Part 'AirplanePlus/Parts/Engine/Early/51/part/AJEE_NapierLion_Prop' [WRN 20:14:15.393] PartLoader Warning: Variable base_dia