I have already installed VS2017 Enterprise 15.6.4. Recently installed .NET Core 2.1.101 SDK from official site
I was expecting .NET Core 2.1 as one of the target framework available if I create console or asp.net core application. Can someone help me understanding what I am missing here.
As suggested in comments, I installed 15.7 preview 2. Still no luck and same issue.
I have faced the same problem. I solved this by installing the right SDKs with Runtime for .NET Core 2.1.
Basically to run/create 2.1 projects from VS Preview, you need to install the "2.1.300" (not 2.1.4) .NET Core SDKs and Runtime. https://www.microsoft.com/net/download/dotnet-core/sdk-2.1.300-preview1 (this includes required Runtime already)
The good explanation of this misleading with versions i found here https://github.com/dotnet/cli/issues/8309 (dasMulli commented on Feb 24).
In case this helps someone else... After installing VS 15.9.2 my project that was working fine with 2.2 preview-3 stopped working. VS could not see the preview SDK. I could build the solution using dotnet.exe but not VS.
To solve this I created a global.json at the root folder of this solution pointing to the preview sdk. That allowed VS to see the preview version.
This is a change of behavior in VS between 15.8.x and 15.9.x.
To create the global.json you can navigate to the desired folder and type this:
dotnet new globaljson
Make sure dotnet PATH variables are in correct order
If you have installed an SDK for a different system architecture (e.g., if you installed 32-bit/x86 SDK on a 64-bit computer), then a new entry in the PATH variable would have been created for that specific location (e.g., C:\Program Files\dotnet or C:\Program Files (x86)\dotnet).
The problem is that Visual Studio, when searching for installed frameworks, will stop at the first PATH variable entry it finds that contains an SDK. So, if the first version you installed used an incorrect architecture, then you'll have to adjust the position of those entries before any of the correct SDKs will appear in the Target Framework drop down.
Source: this absurdly-hard-to-find comment within issue #8309.
TL;DR: Make sure the first "C:\Program Files\dotnet\" entry in your path variable you see in the list matches your system architecture:
64-bit = C:\Program Files\dotnet\
32-bit = C:\Program Files (x86)\dotnet\
Make sure that Visual Studio 2017 is up to date. Go to "Tools" -> "Extensions and Updates" to install visual studio updates. This resolved the issue for me.
I have faced the similar situation I tried to install the preview version of the dot net but it did not help.
However after I updated visual studio (from 15.8 to 15.9.6 ).
I Could see dot net core 2.1 in the target framework.
Updated to Latest VS 2017 and installed latest .Net Core SDK.
Changed global.json to point to latest version installed.
This resolved for me.
I had faced the similar issue. I then just updated my Visual Studio 2017 to 15.9.16 version and restarted the system. The problem got resolved.
I was facing the similar issue, I uninstalled the .Net Core 2.2 runtime and then from the below link:
https://dotnet.microsoft.com/download/visual-studio-sdks?utm_source=getdotnetsdk&utm_medium=referral
Install the .Net Core 2.2 Visual Studio SDK, Restarted the Visual Studio and my issue got resolved, .Net Core 2.2 is now getting listed in Target Framework list in the project properties in Visual Studio 2017 Version 15.9.16
I created a new project under .net core 2.1 and it was ok but in my old project have not appeared. So I opened both ".cproject" files and compared them together and found the problem.
Open your project's ".cproject" file in a text editor then replace below line
<TargetFramework>netstandard2.1</TargetFramework>
with this one:
<TargetFramework>netcoreapp2.1</TargetFramework>
I am not understanding why am I getting above mentioned error while loading some new pulled project from tfs. Even though I have Microsoft DNX folder in my explorer it asks me to install DNX SDK and when I install it fails.
I tried updating visual studio also but it didn't work.
Can anyone help me with this?
Since I use VS 2015, above mentioned issue resolved for me by downloading specific .Net Core version from https://go.microsoft.com/fwlink/?LinkID=827546 . It gives you DotNetCore.1.0.1-VS2015Tools.Preview2.0.3.exe
You can get other related .Net Core SDKs from https://www.microsoft.com/net/download/core
If you have VS 2017, you don't need to install .Net Core SDK explicitly. You get it by default in VS 17.
Cheers!
I have installed the visual studio 2017 for ASP.Net Core. I created Dot Net Core project. Build it successfully and run it but on Firefox it shows the blank page and on chrome it shows "**The localhost page isn’t working
localhost is currently unable to handle this request"
I thought there is a problem in code. I debugged the code and there is nothing wrong with the code. It's the default template and code generated for Asp.Net Core. I googled and tried many things like restart the VS, removed cache, etc but nothing worked for me. Then i uninstalled the VS 2017 and used C Cleaner to remove all temp files etc and installed the visual studio 2017 again but the same error came again. Then i created MVC application, console application in VS 2017 and both worked fine. Issue comes only in Asp.net core application. I use fiddler to see the request status and it is 500. I debugged the code but nothing wrong with the code(No Exception). I have tried many things but did not find anything helpful. Can anyone tell me what's the issue?
The blank page response can be caused by a number of reasons. Sometimes because you are lacking something in the system , routing issues, wrong code on the wrong location, .csproj configuration issues, permission issues, and many more.
There are a couple of things you can try:
Check to see if you have the appropriate ASP.NET Core Module installed in you system. (Either x86 or x64 depending on your system )
Make sure you have enabled IIS Integration in your code
See if you have the error middleware in your Configure code, it mostly helps to solve your issues by giving full detail.
Looks like you are running into error similar to this issue with browserlink .What version of browser link package do you have in your machine
Microsoft.VisualStudio.Web.BrowserLink should be 1.0.1 referring the templates
This SO post discuss the similar issue .If that does not solve, Please make sure you have 1.0.1 in your project referenced and then try this
Clearing your NuGet cache
dotnet nuget locals all --clear
Set Environment variable DOTNET_SKIP_FIRST_TIME_EXPERIENCE to 1 . This is to avoid caching packages
dotnet restore
Does it happens to be runtime compilation issues?
I stumble across this issues log while studying the feasibility of using ASP.Net Core for ERP System host on LinuxOS.
Issues #2017 on GitHub
Try setting
<PreserveCompilationContext>false<PreserveCompilationContext>
in your csproj
I've installed the newly released version of Visual Studio 2017 and started a fresh ASP.NET Core project targeting .NET Core.
Out of the box, I'm getting the
The type or namespace name 'System' could not be found (are you
missing a using directive or an assembly reference?)
error. Any idea what's causing this and how to fix it?
Also, looks like there are problems with NuGet packages as well:
I also tried dotnet restore on the project through the command line and got the following error:
P.S. Kind of disheartening that you get an error in a fresh new project in the latest version of Visual Studio 2017!
UPDATE:
SDK version is v 1.0.1 -- see below:
UPDATE 2:
This is very strange. Looks like the original problem was due to NuGet package source pointing to a folder under Visual Studio 2015 folder. I unchecked it and left only nuget.org. With that my project seemed to have restored all the packages and when I started the project it loads up the standard ASP.NET page. But if I open startup.cs file, I get red squigglies all over the place but if I run the project, it works fine. What's going on here?
UPDATE 3:
I closed the project and VS 2017. I then restarted VS 2017 and opened the project and now it seems to be fine. And I'm not referencing the .NETStandard library 1.6.1 and everything seems to be working fine now.
I had the same issue in my Visual studio 2017 .Net Core application. I closed the Visual studio and re-open fixed everything.
Came across the same issue today. I had an old nuget source that no longer existed. So I went into Tools > Nuget Packet Manager and un-checked the wrong one. Hit "Ok", and then rebuilt the project, and it works great now. It seems like you stumbled onto it, but also wanted to verify that it fixed my issue, and it does.
I had the same problem, first when converting a VS2015 net core mvc web project to 2017 and then when trying to create a new core web application in 2017.
Went to Tools|NuGet Package Manager|Package Manager Settings - checked 'Allow NuGet to download missing packages' and 'Automatically check for missing packages during build in VS' and then clicked 'Clear All NuGet Cache(s)'.
Then re-built the solution - it found and loaded all the required packages and ran OK.
May not work for all cases but simple and worth a try.
Multiple closing and reopening of VS2017 fixed it for me.
I had the same issue, the solution for me was to clear the NuGet cache. Tools > NuGet Package Manager > Package Manager Settings > Clear All NuGet Cache(s)
Check the version .NET Command Line Tools in CMD, just type dotnet --info. If version is 1.0.0, then try to install latest version .NET Core SDK from here.
Find the broken project and right click, Unload, right click, Re-load. Fastest fix for me.
If you get the problem while using the CLI, try doing nuget restore instead of dotnet restore as that sometimes pulls down packages that the dotnet CLI seems to miss.
I have had the same issue with Visual Studio 2019 and .NET Core SDK 2.2.
These steps solved the problem:
Close the Visual Studio
Open the Visual Studio as Administrator
Open the Solution
Right click on Solution -> Restore NuGet Packages
I've tried all answers above. For me works only removal and adding the reference again described in the following steps:
Open 'References' under the project.
Right click on 'System' reference.
Click on 'Remove'.
Right click on 'References'.
Click 'Add Reference...'.
From right menu choose an 'Assemblies',
In a search field type 'System'.
Choose 'System' from the list.
Click 'Add' button.
IMPORTANT: Restart the Visual Studio.
'System' reference you can replace with any you need.
Try adding the following line above the other references in the csproj file
<Reference Include="netstandard" />
For me the problem was caused by my project having a custom IntermediateOutputPath. For some reason, if project_name.csproj.nuget.g.targets is not in obj subfolder of project folder, the error occurs.
Using default IntermediateOutputPath or keeping a shadow copy of project_name.csproj.nuget.g.targets in fake obj folder solves the problem for me.
This issue seems to be triggered by a myriad of reasons. Mine was caused by cloning directly from VSTS using Git Bash, my project directory had spaces in it. Git Bash changed those spaces in the path to %20. It was throwing off all the references in my project. So for anyone who tried everything else and are at their wits end, make sure %20 is not in the path.
So, I have cloned the repository from github and started getting this error.
It was my project uploaded from another machine. I later realized that I have used the materialdesign packages in my project.
I have uninstalled and reinstalled these packages and it fixed my issue.
Had the same problem. Uninstalled Application Insights from my projects using the nuget package manager. I'm not looking at that yet, I just wanted core and unit tests. Problem solved.
I also had the same problem.
The is no SDK folder under the Dependencies one. Therefore, no Microsoft.NetCore.App libraries !
To solve this problem, in Nuget manager window, install any nuget which depends on .NetCoreApp (you can install for example Microsoft.AspNetCore or BundlerMinifier.Core from the Microsoft Visual Studio Offline Packages source).
The SDK will be restored by the same time.
Once it is back, you can uninstall the previously added nuget. The SDK will remain in place.
Not quite sure in which order vs 2017 trying to resolve packages.
But my situation was following. In my VS2015 I had configured local and 3rd party source for nuget packages, newly installed version of 2017 loaded them too.
https://api.nuget.org/v3/index.json was first in list.
But vs2017 throwed an error that it can't restore .net core libraries from my another local repo.
After I unchecked all of them except https://api.nuget.org/v3/index.json, it had started to working normally.
I had this problem too, but not right now, this steps solved my problem: Choose Project -> Properties from the menu bar. In the Project properties window, under Configuration Properties -> General, make sure that Common Language Runtime Support is set to Common Language Runtime Support (/clr)
Simply opening the NuGet package manager and then the Visual Studio settings related to it - without changing anything - merely looking around, and when I closed out, the problem was gone.
This seems to be an intermittent issue that can come and go for no obvious reason.
None of the answers here worked for me so I'm posting what did work.
My errors were mostly the same as the original poster but I also had:
Error loading meta data for 'Microsoft.Extensions.FileProviders.Embedded.2.0.1'
hexadecimal value 0x1C invalid character
Every time I attempted to download a different nuget package or restore old packages I would see this error. I also saw the other errors such as:
type or namespace system could not be found
What worked for me:
opened the filepath that the error said the bad metadata was in, which for me was C:\Program Files\dotnet\sdk\NuGetFallbackFolder\microsoft.extensions.fileproviders.embedded\2.0.1
Then, I put the contents of that folder into another folder I named "hiding".
Then, I went back to the nuget package manager and tried to install a package, hoping to have the SDK restored. IOt worked successfully, and all my other errors were gone as well, and the fresh new project runs as it should!
The problem for me occurred when running my Visual Studio as Admin with a separate user-- I had created a Git Repo with the source files in the user documents of my normal account. When I created a new solution in that folder the above errors occurred. Try creating your project in a different place and see if the error still occurs.
I was facing the same issue when I created a new project (.net Core 2.2) in VS2019.In my case there was an Azure package which was creating the problem.I uninstalled it and the project started working fine.
Run mentioned below command to uninstall the package.
Uninstall-Package Microsoft.VisualStudio.Azure.Containers.Tools.Targets -Version 1.7.10
I had the same problem. I cloned a github project and this error came. So I deleted the cloned project and then I cloned the project again and it worked fine.
I have a Build server which has TFS 2010 Build Service installed. I have 2 Build Agents and 1 Controllers configured. One of our projects have been converted to Visual Studio 2012.
I found out that .NET framework 4.5 comes with new version of MSBuild which is version 4.5.
I installed .NET framework 4.5 on the Build Server because prior to installing it every time the project was built I kept getting the following error:
"Solution is of version '12.00' which is not currently supported".
After installing .NET 4.5, I still run into the same issue.
How could I go about resolving this?
Do I have to configure the Build Agent to use the new MSBuild 4.5 in order to build this particular project or do I set something in the projects solution file itself? If so how?
I would really appreciate if somebody could assist me with this please?
Try install vs2012 on the build server, while i don't believe it's strictly needed it's the easiest way to get all the requirements installed.
We have installed VS2012 on the build agent. Interestingly when I RDC to the build agent and then run msbuild from the command line everything works fine. So the issue looks like it happens before we even get to MSBuild.