Yes Dear the error is self explanatory.
See you have a model inside another model. That is Viewmodel contains a list of Posts, which has FNamePost and ID_Post as properties.
So in the viewpage when you need to access the properties of Post which is a list, you need to have a foreach loop for each item in @Model.PostPoages
@foreach(var item in Model.PostPoages)
As here in the view the Model contains the Postpages whosepropeties need to be accessed through the PostPoages only.
I hope youget here.
Post back queries if any.