Configuration Error related to targetFramework in web.config

Question

I have made an MVC website in Visual Studio 2015 and it works in my localhost. But when I published my website and put into my host, it doesn't work. It gives me this error notice:

Server Error in '/' Application.

Configuration Error

Parser Error Message: The 'targetFramework' attribute in the element of the Web.config file is used only to target version 4.0 and later of the .NET Framework (for example, ''). The 'targetFramework' attribute currently references a version that is later than the installed version of the .NET Framework. Specify a valid target version of the .NET Framework, or install the required version of the .NET Framework.

Source Error:

An application error occurred on the server. The current custom error settings for this application prevent the details of the application error from being viewed remotely (for security reasons). It could, however, be viewed by browsers running on the local server machine.

Source File: G:\xxx\xxx.com\httpdocs\web.config Line: 24

Version Information: Microsoft .NET Framework Version:4.0.30319; ASP.NET Version:4.0.30319.34248

Related parts in my web.config:

  <configSections>
    <section name="entityFramework" type="System.Data.Entity.Internal.ConfigFile.EntityFrameworkSection, EntityFramework, Version=6.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089" requirePermission="false" />
  <!-- For more information on Entity Framework configuration, visit http://go.microsoft.com/fwlink/?LinkID=237468 --></configSections>

And this part with error:

  <system.web>
    <authentication mode="None" />
    <customErrors mode="Off" />
    <compilation debug="true" targetFramework="4.6" />
    <httpRuntime targetFramework="4.6" />
  </system.web>

Properties of my website:

And NuGet Package Manager:

EntityFramework Reference Properties:

Default Web Site Basic Settings: (To be honest, I am not sure whether I should add a new website(my website) in here.)

My installed .net frameworks:

My publish method:

I have investigated this problem on the Internet and I have found several links related to my problem: Asp.net MCV4 framework issue. In this link, there are two main offers:

1. changing this compilation tag

2. updating application pool in IIS

Actually, I have tried to change this tag but it doesn't change. Then I have controlled my application pool but it seems up-to-date.

I have called my host provider and I have explained my problem. They say that this error is not related to their servers.

What should I do? What is the solution for this?

Answer 1

Your website project is targeting v4.6 of the .Net Framework but your hosting provider has not yet installed this version. Your options:

1. Ask provider to install it - they are unlikely to do this.
2. Find another provider that does support it.
3. Change your project to target v4.5.

Answer 2

@DavidG has rightly pointed all the things. Just on informational side if IIS is your provider then Web Platform Installer is your best bet to check the current state of what all is installed on your machine currently. Have a look at the below snapshot -

It is really handy to check what all is missing and you can kick-start installation of all the missing pieces in one click.

Answer 3

I just had a similar problem following the installation ( windows update) of the KB 3205402.

Big difference with my case: the application worked well before the update !

==> I found in "IIS Manager", in "ISAPI and CGI Restrictions", that the framework ASP.NET v4.0.30319 has been switched to "unauthorized" !

Switching it to "Authorized" resolved my problem

Answer 4

had the same issue on the below line on an offline server ,

 <compilation targetFramework="4.5.2">

tried adding all the roles and features related to .Net framework from the server manager and to its pool ,

but didn't work , what worked for me is just downloading Microsoft .NET Framework 4.5.2(Offline Installer)

Answer 5

I went round and round with this today with no resolution. Exasperated, I finally just deleted my working copy from my drive, and rechecked it out from SVN.

Fixed.

Not a particularly clever answer, but it fixed it for me, no idea what the actual problem was.

Answer 6

I changed:

<system.web>
    <compilation debug="true" targetFramework="4.7" />
    <httpRuntime targetFramework="4.7" />
    <customErrors mode="Off"/>
  </system.web>

to

<system.web>
     <compilation debug="true" targetFramework="4.5" />
     <httpRuntime targetFramework="4.5" />
     <customErrors mode="Off"/>
</system.web>

i.e, changed targetFramework value to 4.5 (the one supported on server) from 4.7. and worked.

Answer 7

I tried replacing the targetFramework 4.5.2 to targetFramework 4.0 directly in config file. Then it and all the functions work correctly.

Before:

<compilation targetFramework="4.5.2">

After:

<compilation targetFramework="4.0">