Visual Studio Blazor with Entity Framework Core - visual-studio

I have a website where users log in; everything works perfect but when I install any nuget package for Entity Framework Core, it causes the user to get this error upon login:
No MediaTypeFormatter is available to read an object of type 'ServiceResponse`1' from content with media type 'text/plain'.
Whenever I uninstall the package, it works perfectly fine again.

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Entity Framework not appearing in Add New Item list in Visual Studio 2017

I created a new MVC project in Visual Studio 2017. I wanted to add an EDMX file (I will be doing database-first) so right clicked on the project and selected Add|New Item.
However, I cannot find the Entity Framework components that were available in the previous versions of Visual Studio. Does anyone know where they went?
I had a similar issue today after i updated my VS to the latest 2017 version. I tried to open an .edmx file in VS2017 and it didn't show the designer view. So i realised i forgot to select Entity Framework tools during the installation:
Everything is back to normal :)
In .NET Framework-based projects, the Entity Framework 6 templates are still there. However, for .NET Core-based projects, I believe you're expected to use the dotnet ef commands. This includes a means of scaffolding a code-first DbContext from an existing database. See ASP.NET Core - Existing Database.
To verify this, I setup a demo project with the following structure:
The New Item/Data dialog for the .NET Framework project:
Note that there is also an EF POCO Generator template available in the Online templates section that may be of interest to you:
I know this is late, but I ran into the same exact issue. After reading some of the other answers, I realized I had created a .Net project with Standard library instead of the Framework library.
I faced this issue, while creating an MVC application on my latest installation of VS2017.
Failed:
Tried installing Entity Framework using Nuget package manager[Install-Package EntityFramework], but failed to show Ado.NET Entity data model
Success:
1. open programs under control panel and select Visual Studio 2017
2. select Change the installation
3. Select Modify installation
4. Select Individual components
5. If SQL server data tools already installed, deselect/uninstall this component and reinstall the same again.
6. uninstall and reinstall SQL Server Data tools
Note: with one component change, other components may also be deleted. You have to recheck while reinstalling

Where could a call to an removed property be cached for WebAPI app?

I have a .NET Web API app that has started failing. The error is that it cannot find the setter of a method: set_QueueLocation on a specific class. That was a property on that class, but was removed. This code lives in a NuGet package that I have control over. I searched both solutions (the Web API one and the library with the class used to have QueueLocation property) and QueueLocation does not occur in either of them.
As I mentioned, the library is a NuGet package and when updating, I didn't update the assembly version (just the NuGet version). I'm thinking that when deploying, it looked at the version and then didn't update it. But I can't find out where that might be cached.
I tried :
%LOCALAPPDATA%\Microsoft\WebsiteCache
%LOCALAPPDATA%\Temp\VWDWebCache
C:\Windows\Microsoft.NET\Framework\v4.0.30319\Temporary ASP.NET Files.
I'm on VS 2015, Windows 10 pro. Were would this assembly be cached? Or what else might be causing this issue?
Update
This issue is occurring when I run it in debug mode directly from within VS.

Missing "Ado.Net Entity Data Model" on Visual Studio 2013

I have created new web project but I can't find ADO.net Entity DAta Model to add it.
How to fix it or Install it ?
Go to "C:\ProgramData\Package Cache" and search for "EFTools.msi".
You should find two files, just install the most recent one (it should be about 960KB). This fixed the problem for me.
i have the same problem, but there is no "EFTools.msi" in "C:\ProgramData\Package Cache" for me...
UPDATE :
i download and install "Entity Framework 6 Tools for Visual Studio 2012 & 2013" and it solved the problem \m/
Download Link
Some web tutorials show a 'ADO.NET data entity model' item in the 'Models->Add' menu. In VS2015 this menu item is not shown. You need to keep drilling down by selecting 'New Item...' and then further selecting 'Data' from the pop-up dialog.
My solution was none like the above.
The .msi file was nowhere in the folders suggested in prior answers, nor doing a search in my hard drive found any EFTools.msi instances.
So the failsafe approach came through this article (since the author appears to have completely removed the page from the server, I've changed the URL to a version of the page stored in Google's cache), which was poorly written by a chinese fella, so I'm gonna try to rewrite the steps in a clearer way:
The solution is as follows:
Open your VS2013 installation ISO (or pop the DVD in) and navigate to "\packages\EFTools" folder;
There you will find 2 files (a .cab file and a .msi file);
Copy both files to a directory on your hard drive;
[Optional]: You can create in that same directory, an empty .txt file ("Log.txt") so that the installation log output will be redirected to it later;
Open a MS-DOS command prompt (with administrative rights) and type the command: EFTools.msi USING_EXUIH=1 /log "Log.txt" [NOTE: If you did not perform step #4, then you do not need to type from the ' /log' on (inclusive)]
Wait patiently while the installation process finishes. Takes quite some time (guess never hurts to remind you that this needs to be done with VS2013 closed). The installation should go fine, anything weird will be logged into the text file (the one you created in step #4).
Or, you might just double-click the .msi file if you are feeling brave..
After installation, open VS2013 and try adding a new item to the Models folder. The "ADO.NET Entity Data Model" should have reappeared under the "Data" tab.
Recognition goes to the anonymous chinese poster on that link (er, "Melinda"?) - xiè-xiè!
Be sure you are trying to do that in .Net Framework project. For example, when you are creating a project do not use a template called Windows Forms App (.Net Core), use Windows Forms (.Net Framework). The (.Net Framework) extension is important.
right click on your project--> properties---> framework target select 4.5 and should work.
It's only for Visual Studio 2012. For me this had no effect on 2013.
For the record, if you have Visual Studio 2015 RC, the "EFTools.msi" can't be downloaded from Microsoft
If you accidentally delete the "ProgramData" folder, the Repair option will not work, you have to use the Add or Remove features option from the installer, and check the SQL Server Data Tools
Make sure the type of project you've added is for .NET Framework and not for .NET Standard. The templates for adding things such as ADO.NET Entity Data Model are included for .NET Framework.
For Visual Studio 2017 the following works.
Create project:
Create new project of type 'Class Library'
Install 'Entity Framework' from NuGet
Now add datamodel:
In project click 'Add New Item'
Select 'Visual C# Items' -> 'ADO.NET Entity Data Model'
I recently added Entity Framework and installed in one of my many projects in a single sln file.
The thing is Entity Framework works on Framework higher than 3.5.
So Class Library of NET Standard wouldn't support Entity Framework, thus missing Ado.Net Entity Data Model, Since NET Standard console Library is Framework 2.0, changing the class Library to .NET Framework one, will include Ado.Net Entity Data Model.
I had the same issue, but found out that I was selecting ASP.NET Core web App, ASP.NET Core web App(MVC) etc, Instead Choose ASP.NET Web Application (.NET Framework) and you will get the ADO.NET Entity Data Model option.
Go to visual studio installer.
Add:
Entity framework tool 6
Download and install it.

how can i use Entity Framework 4.1 in Visual Studio 2012?

I have a web application on a web farm and i use .NET 4 and entity data model 4.1.
when i started working on this web application i used visual studio 2010, and today i have uninstalled it and installed new version (Visual Studio 2012).
Due to some reasons, i have deleted my ado.net entity data model to recreate it, but i
pay attention that visual studio 2012 use entity framework 5 not 4.1. I have updated it but in old model i can context constructor to change my connection string but in this new model have no constructor, is that true?
I have installed EF 4.1 but it doesn't works and I've added version 5 to my project.
Background info: my web application is on a shared host and i can not update it to EF 5.
How can i use entity framework 4.1 in visual studio 2012 ?
is that possible? if yes, how?
Remove Existing (Entity framework 5)
Remove the existing reference (to Entity framework 5) under the References section in your Project in Solution explorer.
Remove the corresponding entry from your packages.config file. If you open the packages.config file, you will see an xml structure and you will see an element with id EntityFramework with version attribute value as 5.0.0. Remove that line( that package element).
Add Again (Entity framework 4.1)
Now go to the package manager window(View->Other Windows -> Package Manager Console) and execute the following command there.
Install-Package EntityFramework -Version 4.1.10331.0
This will download EF 4.1 to your project and you will see the success message like below.
Reference : http://nuget.org/packages/EntityFramework/4.1.10331.0
Always keep in mind that there are a lot of improvements made in EF 5. So consider to consume all those as possible as you can.

I cannot find template ADO.NET Entity Data Model in VS2010

In VS2010, I cannot find the template ADO.NET Entity Data Model from the Data section.
I was doing:
create a silverlight(version 4th) project with a WebSite
right click the web project, Add -> New Item -> Data Section(actually, I tried every one)
But I cannot find it!! It's weird!
Then,
I tried to reset my VS template, it didn't work
Tried to re-install VS2010, and I got the "Successful" message. also I am sure that the ADO.NET Entity Framework has been installed appropriately.
So, is there anything else I can do? can I just install this template to VS?
i believe you can add a ADO.NET Entity Data Model in a windows class library
and reference that library where it is required. but you cannot add the data model in a silverlight library.
Update:
in that case, i presuming the website is atleast targeting version 3.5 of the framework
for vs2010, you can check that the required template is available at the locations below
'%programfiles%\Microsoft Visual Studio 10.0\Common7\IDE\ItemTemplates\CSharp\Data\1033\AdoNetEntityDataModelCSharp.zip'
'%programfiles%\Microsoft Visual Studio 10.0\Common7\IDE\ItemTemplates\VisualBasic\Data\1033\AdoNetEntityDataModelVB.zip'
'%programfiles%\Microsoft Visual Studio 10.0\Common7\IDE\ItemTemplates\Web\CSharp\1033\AdoNetEntityDataModelCSharp_ASPNET.zip'
'%programfiles%\Microsoft Visual Studio 10.0\Common7\IDE\ItemTemplates\Web\VisualBasic\1033\AdoNetEntityDataModelVB_ASPNET.zip'
(in a x64 environment use 'Program Files (x86)' for %programfiles%)
hope that helps.
-ryan

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