Error message "CS5001 Program does not contain a static 'Main' method suitable for an entry point"

Question

Unable to execute the following code error CS5001 Program does not contain a static 'Main' method suitable for an entry point

What does this error message mean?

class Program
{
    static async Task MainAsync(string[] args)
    {
        Account.accountTest accountTest = new Account.accountTest();

        bool result = await accountTest.CreateAccountAsync();
    }
}

I got the same error message because I had `async void Main` instead of `async Task Main` — Eldritch Conundrum, Aug 06 '21 at 14:26

score 192 · Accepted Answer · edited May 29 '23 at 13:35

192

It means that you don't have a suitable entry point for your application at the moment.

That code will nearly work with C# 7.1, but you do need to explicitly enable C# 7.1 in your project file:

<LangVersion>7.1</LangVersion>

or more generally:

<LangVersion>latest</LangVersion>

You also need to rename MainAsync to Main. So for example:

Program.cs:

using System.Threading.Tasks;

class Program
{
    static async Task Main(string[] args)
    {
        await Task.Delay(1000);
    }
}

ConsoleApp.csproj:

<Project Sdk="Microsoft.NET.Sdk">
  <PropertyGroup>
    <OutputType>Exe</OutputType>
    <TargetFramework>netcoreapp2.0</TargetFramework>
    <LangVersion>7.1</LangVersion>
  </PropertyGroup>
</Project>

... builds and runs fine.

edited May 29 '23 at 13:35

riQQ

9,878
7
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66

answered Dec 01 '17 at 07:28

Jon Skeet

1,421,763
867
9,128
9,194

added latest to myproject.csproj still getting the same error. – 001 Dec 01 '17 at 07:40
4

@001: See my edited answer - the LangVersion needs capital L and V, and you need to rename the method as well. – Jon Skeet Dec 01 '17 at 07:44
@Pascal: We need far more information than that to help you. Which exact version of the C# compiler (that's the important bit) are you using? What's the context? – Jon Skeet Dec 21 '17 at 15:41
6

and that was the problem. After I found the Advanced button I saw its set to latest major version(default) which should mean 7.0. I set it directly to 7.2 c# compiler. Then it works :-) – Pascal Dec 28 '17 at 11:07
What is the default LangVersion when left unspecified? – Steven Liekens Apr 29 '18 at 16:36
1

@StevenLiekens The latest major version - so 7.0 at the moment. – Jon Skeet Apr 29 '18 at 20:24
11

This was it for me. Language versions can also be set in the Properties page > Build Tab > Advanced – Stuart May 26 '18 at 10:58
1

@JonSkeet This works fine while building the code, but I get same error while trying to publish the app. Any workaround? – gaurav thakur Jul 11 '18 at 06:39
@gauravthakur: It's very hard to tell without any more information about what kind of project you're working with etc. I suggest you ask a new question with precise details. – Jon Skeet Jul 11 '18 at 08:13
2

Thanks @JonSkeet for your reply :). It was silly mistake on side. I had only change Language version for Debug build and Publish uses Release build. – gaurav thakur Jul 18 '18 at 03:46
1

I lost about 30 minutes before I realized that the release configuration needed the same tweak that got my Debug version compiling. :-) – Wellspring Aug 07 '18 at 21:28
For those still with errors with language set correctly: make sure your Main signature is correct, with Task as a return type instead of void. If, like me, you only add "async" keyword the signature is not valid. – ccalboni Oct 01 '18 at 09:46
how about for aspnetcore console application project. there is no where to define the version. – mokh223 Oct 05 '18 at 04:31
@user2748728: I don't know exactly what you mean by "aspnetcore console application" but if you've got a project file, that's where you put the version. (And I haven't seen anything in .NET Core that *doesn't* have a project file.) – Jon Skeet Oct 05 '18 at 12:11
Cannot believe after all these years this is still the ONLY solution. And BTW, is not even in VS2017 intellisense! – Fandango68 Jan 12 '20 at 06:37
1

@Fandango68: With the latest versions of the .NET Core SDK (now that C# 8 has shipped) you don't need to specify the language version - at least not in VS2019. – Jon Skeet Jan 12 '20 at 08:22
Oddly for me, choosing Latest Version did not work. I ended up setting it to the latest version by selecting it from the dropdown in the Advanced page. Makes no sense, but maybe worth a try if you're stuck. – Brian Sweeney Jul 11 '20 at 22:38
1

Changing Main's return type from void to Task is the piece I was missing. – Jacob Robbins Feb 12 '21 at 19:21

score 2 · Answer 2 · answered Aug 22 '22 at 15:19

2

This may be a stupid answer, but if your intend was to make a Class Library project, make sure you have not created a Console Application project by mistake.

I know of at least one person who's done it.

answered Aug 22 '22 at 15:19

typhon04

2,350
25
22

I was helping a team member work on an MVC project and this was the problem. MVC projects need to have their `Output type` set to `Class Library`. I am guessing it had been changed to `Console Application` inadvertently. – Keith Banner Dec 07 '22 at 17:51

Error message "CS5001 Program does not contain a static 'Main' method suitable for an entry point"

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