'object' does not contain a definition for 'Action'

The error is probably in the place where the partial view call is being passed, which is passing an object that does not have the Action property to the _ExternalLoginsListPartial.cshtml view.

Probably on your _ExternalLoginsListPartial.cshtml you are getting a dynamic model like this:

@model dynamic

And referring to the Model.Action property, and the Action property does not exist on the object you are passing from your controller to your partial-view.

return View(objeto_que_nao_possui_action);

or

 @Html.Partial("_ExternalLoginsListPartial", objeto_que_nao_possui_action)

Being objeto_que_nao_possui_action is the object to be investigated.