DbEntityValidationException on SaveChanges

When I run my program I get the error below. In addition my wrong codes that is Record database. What do I do in this situation? My values are not null.

satırenter code here {}## System.Data.Entity.Validation.DbEntityValidationException becomes

HResult=0x80131920 İleti=Validation failed for one or more entities. See 'EntityValidationErrors' property for more details.

My code db.SaveChanges();