On submit click getting issue in umbraco

Question

I have one submit click on which the comment get submitted for particular product or thing but on clicking that I am not able to submit that commnet and facing issue as seen in below images

Another thing is that this things are working properly in my local host but when I upload it on my beta/staging/Live server I am facing this issue. I have also tried deleting umbraco.config file and log file but still facing same issue

Also on log file I can see the issue as

I have one issue for what i assume both issue are interlink to each other Umbraco on save and publishing showing error

My controller code

using System;
using System.Collections.Generic;
using System.Globalization;
using System.Linq;
using System.Web;
using System.Net;
using System.Net.Http;
using System.Text.RegularExpressions;
using System.Web.Mvc;
using Newtonsoft.Json.Linq;
using umbraco;
using Umbraco.Core.Logging;
using Umbraco.Core.Models;
using Umbraco.Web.WebApi;
using xyz.Controls;
using System.Data.SqlClient;
using System.Net.Mail;

namespace xyz.Controllers
{
  public class CommentsController : UmbracoApiController
  {


  }
}

Answer 1

The issue was resolved while going in to Machine.Config of sql server and updating the syntax as

<connectionStrings>
<remove name="LocalMySqlServer"/>
<add name="LocalMySqlServer" connectionString="Datasource=localhost;Database=users;uid=root;pwd=password;"
   providerName="MySql.Data.MySqlClient"/>
</connectionStrings>