How to solve erroe 428C9 in ASP.NET Core MVC? - asp.net-core-mvc

Question

I made a new function for my website.It can do the job like save as.
And it can work will.
But when I create a new project, it suddenly can't work,and show the error 428C9.
What should I do? Can someone give me advice?
It is .cshtml
<div class="row">
<div class="col-xl-10">
<form asp-action="Saveas">
<div asp-validation-summary="ModelOnly" class="text-danger"></div>
<div class="form-group">
<label asp-for="IpAddress" class="control-label"></label>
<input asp-for="IpAddress" class="form-control" />
<span asp-validation-for="IpAddress" class="text-danger"></span>
</div>
<div class="form-group">
<label asp-for="Protocol" class="control-label"></label>
<input asp-for="Protocol" class="form-control" />
<span asp-validation-for="Protocol" class="text-danger"></span>
</div>
<div class="form-group">
<label asp-for="ToolHostPort" class="control-label"></label>
<input asp-for="ToolHostPort" class="form-control" />
<span asp-validation-for="ToolHostPort" class="text-danger"></span>
</div>
<div class="form-group">
<label asp-for="ToolSvid" class="control-label"></label>
<input asp-for="ToolSvid" class="form-control" />
<span asp-validation-for="ToolSvid" class="text-danger"></span>
</div>
<div class="form-group">
<label asp-for="Pid" class="control-label"></label>
<input asp-for="Pid" class="form-control" />
<span asp-validation-for="Pid" class="text-danger"></span>
</div>
<input type="hidden" asp-for="Pid" />
<div class="form-group">
<input type="submit" value="Save" class="btn btn-primary" />
</div>
</form>
</div>
</div>
<div>
<a asp-action="Index">Back to List</a>
</div>
#section Scripts {
#{await Html.RenderPartialAsync("_ValidationScriptsPartial");}
}
It is controller
public async Task<IActionResult> Saveas(int? id)
{
if (id == null)
{
return NotFound();
}
var gatewaySettingCloud = await _context.GatewaySettingClouds.FindAsync(id);
if (gatewaySettingCloud == null)
{
return NotFound();
}
return View(gatewaySettingCloud);
}
[HttpPost]
[ValidateAntiForgeryToken]
public async Task<IActionResult> Saveas([Bind("Ipaddress,Protocol,Toolhostport,Toolsvid,Pid")] GatewaySettingCloud gatewaySettingCloud)
{
if (ModelState.IsValid)
{
_context.Add(gatewaySettingCloud);
await _context.SaveChangesAsync();
return RedirectToAction(nameof(Index));
}
return View(gatewaySettingCloud);
}

Answer 1

I find the database does not accept from applications, so I create a new column replace original column which one can't accept data from applications.Then I can insert the data successful!!
Helper:Karl-Johan Sjögren、Tiny Wang