Cannot post update to database. not all code paths return a value - asp.net

Question

[HttpPost]
public ActionResult UpdateDetail(User user)
{
bool Status = false;
string message = "";
// Model Validation
if (ModelState.IsValid)
{
using (UsersDatabaseEntities ude = new UsersDatabaseEntities())
{
var v = ude.Users.Where(a => a.Email == User.Identity.Name).FirstOrDefault();
user = v;
ude.Entry(User).State = EntityState.Modified;
ude.SaveChanges();
}
return View(user);
}
}
I keep on getting an error while saving data to the database.
UpdateDetail worked while retrieving message, but i keep getting error when saving.

Answer 1

Your issue is if your ModelState.IsValid == false, then you are not returning anything. I put a comment in code below where it is.
Depending on what your logic needs to do, would determine what needs to be returned if IsValid == false
public ActionResult UpdateDetail(User user)
{
bool Status = false;
string message = "";
// Model Validation
if (ModelState.IsValid)
{
using (UsersDatabaseEntities ude = new UsersDatabaseEntities())
{
var v = ude.Users.Where(a => a.Email == User.Identity.Name).FirstOrDefault();
user = v;
ude.Entry(User).State = EntityState.Modified;
ude.SaveChanges();
}
// this is your issue, this needs to be outisde the if statement, or you have to do an else and return null (or whatever you need to based off your logic)
return View(user);
}
}

Answer 2

Keep return statement outside of If statement. this would fix your error.If model is valid model updated with user details from database will be pushed to View. other wise same user model will be pushed to the view.
[HttpPost]
public ActionResult UpdateDetail(User user)
{
bool Status = false;
string message = "";
// Model Validation
if (ModelState.IsValid)
{
using (UsersDatabaseEntities ude = new UsersDatabaseEntities())
{
var v = ude.Users.Where(a => a.Email == User.Identity.Name).FirstOrDefault();
user = v;
ude.Entry(User).State = EntityState.Modified;
ude.SaveChanges();
}
}
return View(user);
}