I am installing an application, following a developer tutorial, but when opening the web this error appears.

I don't have any knowledge in programming. I was reading all the posts related to the subject, but I can't solve my problem. I enclose the information I have.

Web Error:

Unable to update database to match the current model because there are pending changes and automatic migration is disabled. Either write the pending model changes to a code-based migration or enable automatic migration. Set DbMigrationsConfiguration.AutomaticMigrationsEnabled to true to enable automatic migration. Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code.

Exception Details:

System.Data.Entity.Migrations.Infrastructure.AutomaticMigrationsDisabledException: Unable to update database to match the current model because there are pending changes and automatic migration is disabled. Either write the pending model changes to a code-based migration or enable automatic migration. Set DbMigrationsConfiguration.AutomaticMigrationsEnabled to true to enable automatic migration.

Source Error:

An unhandled exception was generated during the execution of the current web request. Information regarding the origin and location of the exception can be identified using the exception stack trace below.

Stack Trace:

[AutomaticMigrationsDisabledException: Unable to update database to match the current model because there are pending changes and automatic migration is disabled. Either write the pending model changes to a code-based migration or enable automatic migration. Set DbMigrationsConfiguration.AutomaticMigrationsEnabled to true to enable automatic migration.]
   System.Data.Entity.Migrations.DbMigrator.Upgrade(IEnumerable`1 pendingMigrations, String targetMigrationId, String lastMigrationId) +725
   System.Data.Entity.Migrations.DbMigrator.UpdateInternal(String targetMigration) +602
   System.Data.Entity.Migrations.DbMigrator.EnsureDatabaseExists(Action mustSucceedToKeepDatabase) +578
   System.Data.Entity.Migrations.DbMigrator.Update(String targetMigration) +116
   System.Data.Entity.MigrateDatabaseToLatestVersion`2.InitializeDatabase(TContext context) +148
   System.Data.Entity.Internal.InternalContext.PerformInitializationAction(Action action) +75
   System.Data.Entity.Internal.InternalContext.PerformDatabaseInitialization() +482
   VsomMonitoringTool.Mvc.MvcApplication.Application_Start() +69

[HttpException (0x80004005): Unable to update database to match the current model because there are pending changes and automatic migration is disabled. Either write the pending model changes to a code-based migration or enable automatic migration. Set DbMigrationsConfiguration.AutomaticMigrationsEnabled to true to enable automatic migration.]
   System.Web.HttpApplicationFactory.EnsureAppStartCalledForIntegratedMode(HttpContext context, HttpApplication app) +546
   System.Web.HttpApplication.RegisterEventSubscriptionsWithIIS(IntPtr appContext, HttpContext context, MethodInfo[] handlers) +171
   System.Web.HttpApplication.InitSpecial(HttpApplicationState state, MethodInfo[] handlers, IntPtr appContext, HttpContext context) +173
   System.Web.HttpApplicationFactory.GetSpecialApplicationInstance(IntPtr appContext, HttpContext context) +255
   System.Web.Hosting.PipelineRuntime.InitializeApplication(IntPtr appContext) +347

[HttpException (0x80004005): Unable to update database to match the current model because there are pending changes and automatic migration is disabled. Either write the pending model changes to a code-based migration or enable automatic migration. Set DbMigrationsConfiguration.AutomaticMigrationsEnabled to true to enable automatic migration.]
   System.Web.HttpRuntime.FirstRequestInit(HttpContext context) +552
   System.Web.HttpRuntime.EnsureFirstRequestInit(HttpContext context) +122
   System.Web.HttpRuntime.ProcessRequestNotificationPrivate(IIS7WorkerRequest wr, HttpContext context) +737
-------------------------------------------------------------------------------------------------------

Web.Config

<?xml version="1.0" encoding="utf-8"?>
<!--
  For more information on how to configure your ASP.NET application, please visit
  http://go.microsoft.com/fwlink/?LinkId=301880
  -->
<configuration>
  <configSections>
  <!-- For more information on Entity Framework configuration, visit http://go.microsoft.com/fwlink/?LinkID=237468 -->
  <section name="entityFramework"
    type="System.Data.Entity.Internal.ConfigFile.EntityFrameworkSection, EntityFramework, Version=6.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089" requirePermission="false"/>
  </configSections>
  <connectionStrings>
    <add name="VsomMonitoringToolConnectionString" connectionString="Data Source=localhost\VsomMonitoringDB;Initial Catalog=VsomMonitoringToolDB;User ID=sa;Password=M0n1t0r1ng" providerName="System.Data.SqlClient"/>
    <add name="VsomMonitoringToolConnectionString_DatabasePublish" connectionString="Data Source=localhost\VsomMonitoringDB;Initial Catalog=VsomMonitoringToolDB;User ID=sa;Password=M0n1t0r1ng" providerName="System.Data.SqlClient"/>
  </connectionStrings>
  <appSettings>
    <add key="webpages:Version" value="3.0.0.0"/>
    <add key="webpages:Enabled" value="false"/>
    <add key="ClientValidationEnabled" value="true"/>
    <add key="UnobtrusiveJavaScriptEnabled" value="true"/>
  </appSettings>
  <system.web>
    <!--<authentication mode="None" />-->
    <compilation targetFramework="4.5.2"/>
    <httpRuntime targetFramework="4.5.2"/>
    <membership defaultProvider="SimpleMembershipProvider">
      <providers>
        <clear/>
        <add name="SimpleMembershipProvider" type="WebMatrix.WebData.SimpleMembershipProvider, WebMatrix.WebData"/>
      </providers>
    </membership>
    <roleManager enabled="true"/>
  </system.web>
  <!--<system.webServer>
    <modules>
      <remove name="FormsAuthentication" />
    </modules>
    <validation validateIntegratedModeConfiguration="false" />
  </system.webServer>-->
  <runtime>
    <assemblyBinding xmlns="urn:schemas-microsoft-com:asm.v1">
      <!--<dependentAssembly>
        <assemblyIdentity name="Microsoft.Owin.Security" publicKeyToken="31bf3856ad364e35" />
        <bindingRedirect oldVersion="0.0.0.0-3.0.1.0" newVersion="3.0.1.0" />
      </dependentAssembly>
      <dependentAssembly>
        <assemblyIdentity name="Microsoft.Owin.Security.OAuth" publicKeyToken="31bf3856ad364e35" />
        <bindingRedirect oldVersion="0.0.0.0-3.0.1.0" newVersion="3.0.1.0" />
      </dependentAssembly>
      <dependentAssembly>
        <assemblyIdentity name="Microsoft.Owin.Security.Cookies" publicKeyToken="31bf3856ad364e35" />
        <bindingRedirect oldVersion="0.0.0.0-3.0.1.0" newVersion="3.0.1.0" />
      </dependentAssembly>
      <dependentAssembly>
        <assemblyIdentity name="Microsoft.Owin" publicKeyToken="31bf3856ad364e35" />
        <bindingRedirect oldVersion="0.0.0.0-3.0.1.0" newVersion="3.0.1.0" />
      </dependentAssembly>-->
      <dependentAssembly>
        <assemblyIdentity name="Newtonsoft.Json" culture="neutral" publicKeyToken="30ad4fe6b2a6aeed"/>
        <bindingRedirect oldVersion="0.0.0.0-6.0.0.0" newVersion="6.0.0.0"/>
      </dependentAssembly>
      <dependentAssembly>
        <assemblyIdentity name="System.Web.Optimization" publicKeyToken="31bf3856ad364e35"/>
        <bindingRedirect oldVersion="1.0.0.0-1.1.0.0" newVersion="1.1.0.0"/>
      </dependentAssembly>
      <dependentAssembly>
        <assemblyIdentity name="WebGrease" publicKeyToken="31bf3856ad364e35"/>
        <bindingRedirect oldVersion="0.0.0.0-1.5.2.14234" newVersion="1.5.2.14234"/>
      </dependentAssembly>
      <dependentAssembly>
        <assemblyIdentity name="System.Web.Mvc" publicKeyToken="31bf3856ad364e35"/>
        <bindingRedirect oldVersion="0.0.0.0-5.2.3.0" newVersion="5.2.3.0"/>
      </dependentAssembly>
      <dependentAssembly>
        <assemblyIdentity name="WebMatrix.Data" publicKeyToken="31bf3856ad364e35" culture="neutral"/>
        <bindingRedirect oldVersion="0.0.0.0-1.0.0.0" newVersion="1.0.0.0"/>
      </dependentAssembly>
      <dependentAssembly>
        <assemblyIdentity name="System.Web.Helpers" publicKeyToken="31bf3856ad364e35"/>
        <bindingRedirect oldVersion="1.0.0.0-3.0.0.0" newVersion="3.0.0.0"/>
      </dependentAssembly>
      <dependentAssembly>
        <assemblyIdentity name="System.Web.WebPages" publicKeyToken="31bf3856ad364e35"/>
        <bindingRedirect oldVersion="0.0.0.0-3.0.0.0" newVersion="3.0.0.0"/>
      </dependentAssembly>
    </assemblyBinding>
  </runtime>
  <entityFramework>
    <defaultConnectionFactory type="System.Data.Entity.Infrastructure.LocalDbConnectionFactory, EntityFramework"/>
    <providers>
      <provider invariantName="System.Data.SqlClient" type="System.Data.Entity.SqlServer.SqlProviderServices, EntityFramework.SqlServer"/>
    </providers>
    <contexts>
      <context type="VsomMonitoringTool.DataAccess.VsomMonitoringToolContext, VsomMonitoringTool.DataAccess">
        <databaseInitializer type="System.Data.Entity.MigrateDatabaseToLatestVersion`2[[VsomMonitoringTool.DataAccess.VsomMonitoringToolContext, VsomMonitoringTool.DataAccess], [VsomMonitoringTool.DataAccess.Migrations.Configuration, VsomMonitoringTool.DataAccess]], EntityFramework, PublicKeyToken=b77a5c561934e089">
          <parameters>
            <parameter value="VsomMonitoringToolConnectionString_DatabasePublish"/>
          </parameters>
        </databaseInitializer>
      </context>
    </contexts>
  </entityFramework>
  <system.codedom>
    <compilers>
      <compiler language="c#;cs;csharp" extension=".cs" type="Microsoft.CodeDom.Providers.DotNetCompilerPlatform.CSharpCodeProvider, Microsoft.CodeDom.Providers.DotNetCompilerPlatform, Version=1.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" warningLevel="4" compilerOptions="/langversion:6 /nowarn:1659;1699;1701"/>
      <compiler language="vb;vbs;visualbasic;vbscript" extension=".vb" type="Microsoft.CodeDom.Providers.DotNetCompilerPlatform.VBCodeProvider, Microsoft.CodeDom.Providers.DotNetCompilerPlatform, Version=1.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" warningLevel="4" compilerOptions="/langversion:14 /nowarn:41008 /define:_MYTYPE=\&quot;Web\&quot; /optionInfer+"/>
    </compilers>
  </system.codedom>
</configuration>
<!--ProjectGuid: {465DCAD8-36C2-40E2-A742-9EC8BFCA8B9C}-->

There are several ways of handling with this problem, and more than one problems may causing this.

But you can try this approach, first Add-Migration and name it Empty.

And when your Migration is created, check if it contains any code in it, and if it has contains any extra or duplicate code, just delete it.

It should look like this:

public partial class Empty : DbMigration
{
    public override void Up()
    {
    }

    public override void Down()
    {
    }
}

And try it now.