Please any one can help me to fix this error?
Schema specified is not valid. Errors:
The mapping of CLR type to EDM type is ambiguous because mult
Just add the EntityFramework as "Code First from database" and not as "EF Designer from database". This resolved my problem, but it has a dark side, if you change your database you have to remove all the classes and add it again, or just edit the classes, I use the last when I change properties of the columns, like "Allows null" or the size of a string. But if you add columns I recomend remove and add again the classes.
There is a library called AutoMapper which you can download. It helps you to define class mappings from one type to another.
Mapper.CreateMap<Model.FileHistoryEFModel, DataTypes.FileHistory>();
Mapper.CreateMap<DataTypes.FileHistory, Model.FileHistoryEFModel>();