Entity Framework: “Store update, insert, or delete statement affected an unexpected number of rows (0).” [closed]

Answer 1

I was facing this same scaring error... :) Then I realized that I was forgetting to set a

@Html.HiddenFor(model => model.UserProfile.UserId)

for the primary key of the object being updated! I tend to forget this simple, but very important thingy!

By the way: HiddenFor is for ASP.NET MVC.