entity framework - EF6 database first - the relationship was not loaded because the type is not available -

i using ef6 database first design in web application. there 1 entity involved in 2 1-to-many relationships (the e2 in example):
e1 <--- e2 ---> e3

e1 , e3 both have navigation property e2 (called e2s). when try listview of e3, error listed in title. if remove navigation property e2 e3, works fine! i've tried looking on google no avail. help/direction appreciated.

added on 5/15:

tmg - hope wanting.

this 'e2' in example:

imports system imports system.collections.generic  partial public class contact     public property contact_id integer     public property implementation_id integer     public property contact_type_id integer     public property name string     public property user_id string     public property is_main_contact boolean     public property email_address string      public overridable property contact_type contact_type     public overridable property implementation implementation  end class 

the next 2 e1 , e3:

imports system imports system.collections.generic  partial public class contact_type     public property contact_type_id integer     public property contact_type_description string      public overridable property contacts icollection(of contact) = new hashset(of contact)  end class 

---

imports system imports system.collections.generic  partial public class implementation     public property implementation_id integer     public property user_id string     public property comments string     public property creation_date nullable(of date)     public property customer_name string     public property customer_global_name string     public property customer_address string     public property customer_country string     public property service_order_number string     public property title string     public property contact_name string      public overridable property country country     public overridable property supportdetail support_detail     public overridable property tradecompliance trade_compliance     public overridable property statuseffdates icollection(of implementation_status_eff_date) = new hashset(of implementation_status_eff_date)     public overridable property hwsdata hws_data     public overridable property documents icollection(of document) = new hashset(of document)     public overridable property contacts icollection(of contact) = new hashset(of contact)  end class 

this list view code:

imports system.web.modelbinding  public class implementationlist     inherits system.web.ui.page      protected sub page_load(byval sender object, byval e system.eventargs) handles me.load      end sub     public function getimplementations(<querystring("id")> categoryid system.nullable(of integer)) iqueryable(of implementation)         dim db = new rfi_sdm.rfi_dataentities         dim query iqueryable(of implementation) = db.implementations         return query     end function end class 

and code rfi_dataentities:

imports system imports system.data.entity imports system.data.entity.infrastructure  partial public class rfi_dataentities     inherits dbcontext      public sub new()         mybase.new("name=rfi_dataentities")     end sub      protected overrides sub onmodelcreating(modelbuilder dbmodelbuilder)         throw new unintentionalcodefirstexception()     end sub      public overridable property countries() dbset(of country)     public overridable property implementations() dbset(of implementation)     public overridable property replacement_type() dbset(of replacement_type)     public overridable property service_level_choice() dbset(of service_level_choice)     public overridable property support_detail() dbset(of support_detail)     public overridable property tat_end_choice() dbset(of tat_end_choice)     public overridable property tat_measurement_basis() dbset(of tat_measurement_basis)     public overridable property tat_start_choice() dbset(of tat_start_choice)     public overridable property regions() dbset(of region)     public overridable property contacts() dbset(of contact)     public overridable property contact_type() dbset(of contact_type)     public overridable property hws_data() dbset(of hws_data)     public overridable property implementation_mgr() dbset(of implementation_mgr)     public overridable property implementation_service_level() dbset(of implementation_service_level)     public overridable property implementation_status() dbset(of implementation_status)     public overridable property implementation_status_eff_date() dbset(of implementation_status_eff_date)     public overridable property trade_compliance() dbset(of trade_compliance)     public overridable property implementation_type() dbset(of implementation_type)     public overridable property documents() dbset(of document)     public overridable property document_type() dbset(of document_type)     public overridable property lcm_data() dbset(of lcm_data)     public overridable property lcm_document() dbset(of lcm_document)  end class 

the actual error i'm getting is:

schema specified not valid. errors: relationship 'rfi_datamodel.fk_contact_contact_type' not loaded because type 'rfi_datamodel.contact' not available.

the relationship 'rfi_datamodel.fk_contact_implementation' not loaded because type 'rfi_datamodel.contact' not available.

if remove 'contact' navigation property contact_type , implementation classes, list view loads without issue.