DataTables部署后出现无效JSON响应错误求助（附代码）

本地运行正常，但部署到Web服务器后，DataTables提示：

DataTables warning: table id=DT_load - Invalid JSON response.

此前遇到404错误，改用命名处理方法（Named Handler methods）后请求状态码变为200，但出现上述无效JSON错误。查阅相关文档后仍无法解决。

systemList.js #

$(document).ready(function () {
    $('#DT_load').DataTable({
        ajax: {
            url: "?handler=SystemsAll",
            type: "GET",          
            dataSrc: '',
            dataType: "json",
        },
        columnDefs: [{
            visible: false,
            searchable: false
        }],
        columns: [
            { "data": "name", "width": "10%"},
            { "data": "website", "width": "10%" },
            { "data": "wiki", "width": "10%" },
            { "data": "lastDeployed", "width": "10%" },
            { "data": "sql", "width": "10%" },
            { "data": "web", "width": "10%" },
            {
                data: "id",
                success: function (data) {
                    console.log(data);
                    return `<div class="text-center">
                        <a href="/AppPages/Update?id=${data}" class='btn btn-success text-white' style='cursor:pointer; width:70px;'>
                            Update
                        </a>
                        &nbsp;
                        <a class='btn btn-danger text-white' style='cursor:pointer; width:70px;'
                            onclick=Delete('/api/system?id='+${data})>
                            Delete
                        </a>
                        </div>`;
                }, width: "40%"
            }
        ],
        language: {
           emptyTable: "no data found"
        },
        width: "100%"
    });
});

HomeController.cs #

using Microsoft.AspNetCore.Mvc;
using Microsoft.EntityFrameworkCore;
using ServiceCatalogue.Model;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;
using System.Linq.Dynamic.Core;

namespace ServiceCatalogue.Controllers
{
    [Produces("application/json")]
    public class HomeController : Controller
    {
        private readonly AppDbContext _db;

        public HomeController(AppDbContext db)
        {
            _db = db;
        }
        
        public async Task<IActionResult> OnGetSystemsAll()
        {
           //var allData = await _db.SystemAsset.ToListAsync();
           // return new JsonResult(allData);
           
           return Json(new { data = await _db.SystemAsset.ToListAsync() });
        }

        public async Task<IActionResult> OnPostDelete(int id)
        {
            var systemFromDb = await _db.SystemAsset.FirstOrDefaultAsync(u => u.Id == id);
            if (systemFromDb == null)
            {
                return Json(new { success = false, message = "Error while Deleting" });
            }
            _db.SystemAsset.Remove(systemFromDb);
            await _db.SaveChangesAsync();
            return Json(new { success = true, message = "Delete successful" });
        }
    }
}

Index.cshtml（注：原内容粘贴重复为HomeController代码，推测此处应为页面视图代码，若有遗漏请补充） #

<!-- 此处应为Index视图的HTML代码，原内容粘贴错误，暂留空 -->

Startup.cs #

using Microsoft.AspNetCore.Builder;
using Microsoft.AspNetCore.Hosting;
using Microsoft.AspNetCore.HttpsPolicy;
using Microsoft.EntityFrameworkCore;
using Microsoft.Extensions.Configuration;
using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.Hosting;
using ServiceCatalogue.Model;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;
using Microsoft.AspNetCore.Mvc;
using Newtonsoft.Json.Serialization;
using System.Text.Json;

namespace ServiceCatalogue
{
    public class Startup
    {
        public Startup(IConfiguration configuration)
        {
            Configuration = configuration;
        }

        public IConfiguration Configuration { get; }

        // 此方法由运行时调用，用于向容器添加服务
        public void ConfigureServices(IServiceCollection services)
        {
            services.Configure<IISServerOptions>(options =>
            {
                options.AutomaticAuthentication = false;
            });
            services.AddDbContext<AppDbContext>(option => option.UseSqlServer(Configuration.GetConnectionString("CatologueDb")));
            services.AddControllersWithViews();
            services.AddMvc()
           .AddNewtonsoftJson(options =>
           options.SerializerSettings.ContractResolver =
              new DefaultContractResolver());
            services.AddRazorPages();
        }

        // 此方法由运行时调用，用于配置HTTP请求管道
        public void Configure(IApplicationBuilder app, IWebHostEnvironment env)
        {
            if (env.IsDevelopment())
            {
                app.UseDeveloperExceptionPage();
            }
            else
            {
                app.UseExceptionHandler("/Error");
                // 默认HSTS值为30天，生产环境可根据需要修改
                app.UseHsts();
            }

            app.UseHttpsRedirection();
            app.UseStaticFiles();

            app.UseRouting();

            app.UseAuthorization();

            app.UseEndpoints(endpoints =>
            {
                endpoints.MapControllers();
                endpoints.MapRazorPages();
            });
        }
    }
}

内容的提问来源于stack exchange，提问作者RumenDimov_1