Cannot delete class definition 'Acad:AcDbEntity'; it has objects 
 Unsupported Schema modification; Cannot make abstract class 'Acad:ElectricDevice' concrete 
 Unsupported Schema modification; Cannot change autogeneration setting for data property 'Acad:ElectricDevice.FeatId' 
 Unsupported Schema modification; Cannot change geometry types for geometric property 'Acad:ElectricDevice.Geometry' 
 Unsupported Schema modification; Cannot change geometry types for geometric property 'Acad:ElectricDevice.Geometry' 
 Unsupported Schema modification; Cannot add/remove elevation dimension to/from geometric property 'Acad:ElectricDevice.Geometry' 
 Unsupported Schema modification; Cannot add/remove measure dimension to/from geometric property 'Acad:ElectricDevice.Geometry' 
 Unsupported Schema modification; Cannot make class 'Acad:Transformer' abstract 
 Unsupported Schema modification; Cannot change base class for 'Acad:Transformer' from 'Acad:ElectricDevice' to '' 
 Unsupported Schema modification; Cannot change data type for property 'Acad:Transformer.Voltage' from 'decimal' to 'string' 
 Unsupported Schema modification; Cannot change property 'Acad:Transformer.Voltage' to be nullable 
 Unsupported Schema modification; Cannot change precision for data property 'Acad:Transformer.Voltage' from '10' to '45' 
 Unsupported Schema modification; Cannot change scale for data property 'Acad:Transformer.Voltage' from '1' to '8' 
 Unsupported Schema modification; Cannot change default value for data property 'Acad:Transformer.Phase' from '' to 'A' 
 Unsupported Schema modification; Cannot change length for data property 'Acad:Transformer.Phase' from '1' to '3' 
 Unsupported Schema modification; Cannot change property 'Acad:Transformer.PartNum' to be not nullable 
 Unsupported Schema modification; Cannot change autogeneration setting for data property 'Acad:Transformer.SerialNum' 
 Unsupported Schema modification; Cannot change property 'Acad:Transformer.SerialNum' to be read-only 
 Cannot add property 'Acad:Transformer.LastRepairDate'; it already exists 
 Cannot delete class definition 'Acad:Conductor'; it has objects 
 Cannot change property type of property 'Acad:Pole.Height'.  
 Cannot modify property 'Acad:Pole.Material'; it does not exist 
 Cannot modify class 'Acad:NoExists'; it does not exist 
 Cannot delete class 'Acad:Customer'; it is the base class for 'Acad:Customer - Residential' 
 Cannot delete class 'Acad:Customer'; it is the base class for 'Acad:Customer - Business'