An error occurred while saving entities that do not expose foreign key properties for their relationships. The EntityEntries property will return null because a single entity cannot be identified as the source of the exception. Handling of exceptions while saving can be made easier by exposing foreign key properties in your entity types. See the InnerException for details.
CUnable to determine the provider name for connection of type '{0}'.
Unable to determine a composite foreign key ordering for foreign key on type {0}. When using the ForeignKey data annotation on composite foreign key properties ensure order is specified by using the Column data annotation or the fluent API.
Unable to determine composite primary key ordering for type '{0}'. Use the ColumnAttribute or the HasKey method to specify an order for composite primary keys.
Unable to determine the principal end of an association between the types '{0}' and '{1}'. The principal end of this association must be explicitly configured using either the relationship fluent API or data annotations.
VUnable to add the convention '{0}'. Could not find an existing convention of type '{1}' in the current convention set.