Develop Reference

Entity Framework gives error "Could not load file or assembly", "FileNotFoundException" every time whenever I reopen visual Studio 2019

I am using visual studio 2019 Ent and EntityFramework.6.4.4.
Whenever I'm restarting my VS19 and going to access EF it gives me the following error with code first approach.
Exception calling "LoadFrom" with "1" argument(s): "Could not load file or assembly 'file:///("Project Name")\packages\EntityFramework.6.4.4\tools\EntityFramework.PowerShell.Utility.dll' or one of its dependencies. The
system cannot find the file specified."
At "(Project Name)"\packages\EntityFramework.6.2.0\tools\EntityFramework.psm1:782 char:5
+ $utilityAssembly = [System.Reflection.Assembly]::LoadFrom((Join-P ...
+ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ CategoryInfo : NotSpecified: (:) [], MethodInvocationException
+ FullyQualifiedErrorId : FileNotFoundException
You cannot call a method on a null-valued expression.
At "(Project Name)"\packages\EntityFramework.6.2.0\tools\EntityFramework.psm1:783 char:5
+ $dispatcher = $utilityAssembly.CreateInstance(
+ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ CategoryInfo : InvalidOperation: (:) [], RuntimeException
+ FullyQualifiedErrorId : InvokeMethodOnNull
Exception calling "CreateInstanceFrom" with "8" argument(s): "Could not load file or assembly 'file:///"(Project Name)"\packages\EntityFramework.6.4.4\tools\EntityFramework.PowerShell.dll' or one of its dependencies. The system
cannot find the file specified."
At "(Project Name)"\packages\EntityFramework.6.2.0\tools\EntityFramework.psm1:811 char:5
+ $domain.CreateInstanceFrom(
+ ~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ CategoryInfo : NotSpecified: (:) [], MethodInvocationException
+ FullyQualifiedErrorId : FileNotFoundException
What I have tried so far:
I found one temporary solution that by reinstalling every time nugete package i.e entity framework and it works.
But this is annoying and definitely not the solution. Looking for a permanent solution.
Thanks in advance.

In my case I was executing the
Add-Migration
command. Instead, I used
EntityFramework6\Add-Migration
And I had no more errors. (Thanks to this answer I found https://stackoverflow.com/a/58951090/2546759)
Another thing which did the trick was:
Make sure that all projects in the solution are using same EF version.
Restart Visual Studio.
(As suggested here: https://stackoverflow.com/a/70004476/2546759)

Asp.Net boilerplate,, How to Move boilerplate project to another Computer?

I was working on ASP.Net boilerplate framework and now that machine is not available where i was working, But i have backup on my Google drive. How i can use that backup properly? Database creation , project running etc???
I am getting error on Enable-Migrations and Update Database Commands
Exception calling "LoadFrom" with "1" argument(s): "Could not load file or assembly 'file:///F:\Qubit
Systems\ShipperBuyerV1\module-zero-template-2.1.1\src\packages\EntityFramework.6.1.3\tools\EntityFramework.PowerShell.Utility.dll' or one of its dependencies. Operation is not supported.
(Exception from HRESULT: 0x80131515)"
At F:\Qubit Systems\ShipperBuyerV1\module-zero-template-2.1.1\src\packages\EntityFramework.6.1.3\tools\EntityFramework.psm1:780 char:5
+ $utilityAssembly = [System.Reflection.Assembly]::LoadFrom((Join-P ...
+ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ CategoryInfo : NotSpecified: (:) [], MethodInvocationException
+ FullyQualifiedErrorId : FileLoadException
You cannot call a method on a null-valued expression.
At F:\Qubit Systems\ShipperBuyerV1\module-zero-template-2.1.1\src\packages\EntityFramework.6.1.3\tools\EntityFramework.psm1:781 char:5
+ $dispatcher = $utilityAssembly.CreateInstance(
+ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ CategoryInfo : InvalidOperation: (:) [], RuntimeException
+ FullyQualifiedErrorId : InvokeMethodOnNull
Exception calling "CreateInstanceFrom" with "8" argument(s): "Could not load file or assembly 'file:///F:\Qubit
Systems\ShipperBuyerV1\module-zero-template-2.1.1\src\packages\EntityFramework.6.1.3\tools\EntityFramework.PowerShell.dll' or one of its dependencies. Operation is not supported. (Exception
from HRESULT: 0x80131515)"
At F:\Qubit Systems\ShipperBuyerV1\module-zero-template-2.1.1\src\packages\EntityFramework.6.1.3\tools\EntityFramework.psm1:809 char:5
+ $domain.CreateInstanceFrom(
+ ~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ CategoryInfo : NotSpecified: (:) [], MethodInvocationException
+ FullyQualifiedErrorId : FileLoadException

Here is what you should do:
Download the project from your Google drive
Open in Visual Studio
Run Database-Update (Make sure the Entity Framework project is selected in the Nuget Package Manager.
That is all you need to do to get. All you will lose is the data in your previous database on the unavailable machine.

Best solution is to create a repo in Git, add you project in it. On there PC run git clone on the desired path.
Refer Setting up git repo

Package Manage Console not working

I am trying to install Npgsql and Npgsql.EntityFramework and getting this error:
Install-Package : The remote name could not be resolved: 'www.nuget.org'
At line:1 char:16
+ Install-Package <<<< Npgsql
+ CategoryInfo : NotSpecified: (:) [Install-Package], WebException
+ FullyQualifiedErrorId : NuGetCmdletUnhandledException,NuGet.PowerShell.Commands.InstallPackageCommand
What am I doing wrong? Please help

OK this is stupid.
Rebooting my laptop actually helped!
Must have been some wifi network error

Error on Enable-Migrations

I'm new with EF and I have an error when I try to run Enable-Migrations in PMC console :
Exception calling "LoadFrom" with "1" argument(s):
"Could not load file or assembly 'file:///...\pa
ckages\EntityFramework.6.0.1\tools\EntityFramework.PowerShell.Utility.dll' or one of its dependencies. Operation is not supported. (Exception from HRESULT: 0x80131515)"
At ...\packages\EntityFramework.6.1.1\tools\EntityFramework.psm1:780 char:62
+ $utilityAssembly = [System.Reflection.Assembly]::LoadFrom <<<< ((Join-Path $ToolsPath EntityFramework.PowerShell.Utility.dll))
+ CategoryInfo : NotSpecified: (:) [], MethodInvocationException
+ FullyQualifiedErrorId : DotNetMethodException
You cannot call a method on a null-valued expression.
At ...\packages\EntityFramework.6.1.1\tools\EntityFramework.psm1:781 char:50
+ $dispatcher = $utilityAssembly.CreateInstance <<<< (
+ CategoryInfo : InvalidOperation: (CreateInstance:String) [], RuntimeException
+ FullyQualifiedErrorId : InvokeMethodOnNull
Exception calling "CreateInstanceFrom" with "8" argument(s): "Could not load file or assembly 'file:///...\packages\EntityFramework.6.0.1\tools\EntityFramework.PowerShell.dll' or one of its dependencies. Operation is no t supported. (Exception from HRESULT: 0x80131515)"
At ...\packages\EntityFramework.6.1.1\tools\EntityFramework.psm1:809 char:31
+ $domain.CreateInstanceFrom <<<< (
+ CategoryInfo : NotSpecified: (:) [], MethodInvocationException
+ FullyQualifiedErrorId : DotNetMethodException

I just ran into this on one of my co-worker's machine. The solution was:
Uninstall EF NuGet package
Manually remove Entity Framework sections from the Web.Config/App.Config files
Close Visual Studio
Re-open the solution in Visual Studio
Reinstall the EF NuGet Package

So openn the solution folder in file explorer, can you find the .dlls they are looking for in "Packages" folder then EntityFramework 6.0.1 folder? If not, there are two options:
Check your source control server, there is a possibility it was not downloaded to local workspace. if so, just get them manually from source control explorer if you are using TFS.
If the files were not on source control server either, I would recommend to uninstall EF 6.0.1 nuget, then manual delete the whole folder about ef in the Package folder above, and then reinstall it.

I had the same problem. My project was stored in a network drive. There are many security policies applied to my PC. I moved my project to the local hard drive, and the problem was solved.
It seems like "EntityFramework.Powershell.utility.dll" is tring to use some powershell functionality, and the system is preventing to execute such calls, maybe because the dll that is calling powershell is not a local file.
In your case, make sure that you do not have any security policy or system configuration that would prevent your system execute the problematical extension from a non local drive (EntityFramework.Powershell.utility.dll)

Faced similar problem. Reason of the problem was shifting of my code from one machine to another...Removing and then reinstalling entity framework solved the problem.

Update the Entity Package from Package Manager Console or browser.

Unable to resolve dependency 'html5shiv'

please help me to resolve this error:
PM> Install-Package twitter.bootstrap.mvc4.sample
Attempting to resolve dependency 'twitter.bootstrap.mvc4'.
Attempting to resolve dependency 'html5shiv'.
Install-Package : Unable to resolve dependency 'html5shiv'.
At line:1 char:16
+ Install-Package <<<< twitter.bootstrap.mvc4.sample
+ CategoryInfo : NotSpecified: (:) [Install-Package], InvalidOperationException
+ FullyQualifiedErrorId : NuGetCmdletUnhandledException,NuGet.PowerShell.Commands.InstallPackageCommand
i want to install twitter.bootstrap.mvc4.samplen.nupkg offline.i add folder path to nuget manager in vs2012.
sorry for my bad english.

Try running Install-Package html5shiv first