.NETCore 2.1 - Target framework disappeared (Windows Update?)

JDias 71

I developed some of my apps in Visual Studio 2019 and with the framework .NET Core 2.1, without major problems. (C#, ASP.NET Core MVC).

However, since a few days ago, I can't open my projects: the framework is missing.

Doing dotnet --list-sdks, it returns an empty list.

In the directory Program Files (x86)\dotnet , there are some file of framework 3.1. It seems that dotnet sees this directory.

In the directory Program Files\dotnet, there are some frameworks (1, 2.1, 3.1). dotnet doesn't see this directory.

What can I do?

Could it be the last update (Windows Update) of the .NET Framework?

2 answers

Michael Taylor 47,966 Reputation points

2022-04-27T14:20:05.547+00:00

.NET Core 2.1 was end of life Aug of last year. While the runtime won't get uninstalled automatically, updates to tooling won't be necessarily looking for it anymore.

.NET Framework is independent of .NET Core and installing/updating/removing one doesn't impact the other. 2.1 still shows up in mine and I'm running 6.0.300-preview.22204.3. You can try running dotnet --list-runtimes and confirm the runtime is still installed, which it should be.

I'm wondering if you are a victim of this reported issue. You should be able to reinstall the .NET Core 2.1 SDK manually to get back to where you were.
Please sign in to rate this answer.

1 person found this answer helpful.
JDias 71 Reputation points

2022-04-27T15:15:52.57+00:00

@Michael Taylor :

Yes, my case is similar, but with different versions of .NET Core and with no recent upgrade of Visual Studio 2019 (I think I never upgraded it...). But this case was not fully closed: no solution is provided!

The runtimes of .NET Core 3.1 are present, but this is not enough.

Do you recomend me to repair my Visual Studio 2019 installation with Visual Studio Installer? Would I lose important data to run my programs?

By the way the needed SDKs and runtimes are installed as I can see in the Settings\Applications (Windows 10 menu). I tried to repair some of them, without much result... However, such runtimes and SDKs are not accessible: they are in a different directory...

Thanks

Michael Taylor 47,966 Reputation points

2022-04-27T16:00:05.477+00:00

Repairing a VS installation won't remove important data but it shouldn't be necessary in this case. Just download and install the SDK directly. It should then show up again in the list. However since it is EOL you may still run into issues where tools are dropping support for 2.1.

JDias 71 Reputation points

2022-04-27T16:40:19.613+00:00

@Michael Taylor :

Unfortunately, I have just installed NET Core 2.1.818 SDK and it was installed in C:\Program Files\dotnet.

The command cli dotnet has simply no access to it, as before!

The result of dotnet --list-sdks is empty!

Do you have any suggestion?

Note: this installation is now in Settings\Application as the others (which are broken as we saw...).

Michael Taylor 47,966 Reputation points

2022-04-27T16:50:32.41+00:00

When you list the SDKs what path(s) is it pulling from?

What version of dotnet tool are you running?

JDias 71 Reputation points

2022-04-28T08:46:41.52+00:00

When I run dotnet --info, I obtain:
Host (useful for support): Version: 3.1.24 Commit: 3b38386083

where dotnet answers:

C:\Program Files (x86)\dotnet\dotnet.exe

As you can figure out, I have another instalation of dotnet of C:\Program Files\dotnet: not accessible, but it is exactly the same version and commit.

C:\Program Files\dotnet\dotnet,exe --info returns:

`
Runtime Environment:
OS Name: Windows
OS Version: 10.0.19043
OS Platform: Windows
RID: win10-x64
Base Path: C:\Program Files\dotnet\sdk\3.1.418\

Host (useful for support):
Version: 3.1.24
Commit: 3b38386083
`

Michael Taylor 47,966 Reputation points

2022-04-28T14:12:45.363+00:00

Ok that is making more sense now. The x64 version of dotnet is the version that is generally used. When you installed the SDK you must have installed the x64 version. There is also an x86 link here. If you want both then you need to install both.

I believe most people use the x64 version of dotnet and therefore I would recommend that you simply change your PATH environment variable to point to C:\program files\dotnet. It sounds like right now you have C:\Program Files (x86)\dotnet which is the x86 version.

JDias 71 Reputation points

2022-04-28T16:05:32.837+00:00

Thanks @Michael Taylor

I added the path C:\Program Files\dotnet to the system path (in Settings), and made it with higher priority than the previous path and all appears to work well.

However, which update did this? This could be a problem for a lot of programmers, couldn't it?

By the way, I just checked both dotnet with dumpbin and one was x64 and the other x86 version.

Michael Taylor 47,966 Reputation points

2022-04-28T16:15:24.133+00:00

I'm not aware of any update doing this as dotnet has had both versions for a while. I'm not aware of anyone reporting this issue elsewhere and I myself haven't seen the issue.

I'm just guessing here that you might have originally installed the x86 version of the .NET Core SDK and hence your system path was updated to point to the x86 version. However that path isn't really needed and you should be able to remove it from your system path. Later when you installed newer SDKs (x86 or x64) then they would potentially update both versions of the binary but not your system path as it was already there. But I'm totally guessing as to how the installer would have worked here.

I myself only have the x64 version of the tool and SDKs installed. However if I were to be developing x86 apps I would also install the x86 version of the SDKs so they could compile.

JDias 71 Reputation points

2022-04-29T08:21:33.94+00:00

Cool! Problem solved! Thanks!
Sign in to comment
Limitless Technology 39,351 Reputation points

2022-04-28T15:58:02.937+00:00

Hello JDias,

Yes, it is highly possible that you have pinned the SDK target version in a global.json file and therefor the project can't find the version after the update.

The next link will show you how is usually the syntax so you can find it in the global.json file:

https://learn.microsoft.com/en-us/dotnet/core/versions/selection#the-sdk-uses-the-latest-installed-version

Hope this helps with your query,

-----------------------------------------------------------------------------------------------------------------------------

--If the reply is helpful, please Upvote and Accept as answer--
Please sign in to rate this answer.

0 comments No comments
Sign in to comment