问题
When try to Install Entity Framework 6.1.3 From Package Manager console. I get following output.
Install-Package EntityFramework
Attempting to gather dependency information for package 'EntityFramework.6.1.3' with respect to project 'OnlineShop', targeting '.NETFramework,Version=v4.6.1'
Attempting to resolve dependencies for package 'EntityFramework.6.1.3' with DependencyBehavior 'Lowest'
Resolving actions to install package 'EntityFramework.6.1.3'
Resolved actions to install package 'EntityFramework.6.1.3'
Adding package 'EntityFramework.6.1.3' to folder 'D:\Leva\Work\Informatika\CSharp\My OPENSOURCE projects\OnlineShop\packages'
Added package 'EntityFramework.6.1.3' to folder 'D:\Leva\Work\Informatika\CSharp\My OPENSOURCE projects\OnlineShop\packages'
Added package 'EntityFramework.6.1.3' to 'packages.config'
Executing script file 'D:\Leva\Work\Informatika\CSharp\My OPENSOURCE projects\OnlineShop\packages\EntityFramework.6.1.3\tools\install.ps1'
Exception calling "LoadFrom" with "1" argument(s): "Could not load file or asse
mbly 'file:///D:\Leva\Work\Informatika\CSharp\My OPENSOURCE projects\OnlineShop
\packages\EntityFramework.6.1.3\tools\EntityFramework.PowerShell.Utility.dll' o
r one of its dependencies. The system cannot find the file specified."
At D:\Leva\Work\Informatika\CSharp\My OPENSOURCE projects\OnlineShop\packages\E
ntityFramework.6.1.3\tools\EntityFramework.psm1:780 char:5
+ $utilityAssembly = [System.Reflection.Assembly]::LoadFrom((Join-Path $Too
lsP ...
+ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
~~~
+ CategoryInfo : NotSpecified: (:) [], MethodInvocationException
+ FullyQualifiedErrorId : FileNotFoundException
You cannot call a method on a null-valued expression.
At D:\Leva\Work\Informatika\CSharp\My OPENSOURCE projects\OnlineShop\packages\E
ntityFramework.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 fi
le or assembly 'file:///D:\Leva\Work\Informatika\CSharp\My OPENSOURCE projects\
OnlineShop\packages\EntityFramework.6.1.3\tools\EntityFramework.PowerShell.dll'
or one of its dependencies. The system cannot find the file specified."
At D:\Leva\Work\Informatika\CSharp\My OPENSOURCE projects\OnlineShop\packages\E
ntityFramework.6.1.3\tools\EntityFramework.psm1:809 char:5
+ $domain.CreateInstanceFrom(
+ ~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ CategoryInfo : NotSpecified: (:) [], MethodInvocationException
+ FullyQualifiedErrorId : FileNotFoundException
Exception calling "LoadFrom" with "1" argument(s): "Could not load file or asse
mbly 'file:///D:\Leva\Work\Informatika\CSharp\My OPENSOURCE projects\OnlineShop
\packages\EntityFramework.6.1.3\tools\EntityFramework.PowerShell.Utility.dll' o
r one of its dependencies. The system cannot find the file specified."
At D:\Leva\Work\Informatika\CSharp\My OPENSOURCE projects\OnlineShop\packages\E
ntityFramework.6.1.3\tools\EntityFramework.psm1:780 char:5
+ $utilityAssembly = [System.Reflection.Assembly]::LoadFrom((Join-Path $Too
lsP ...
+ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
~~~
+ CategoryInfo : NotSpecified: (:) [], MethodInvocationException
+ FullyQualifiedErrorId : FileNotFoundException
You cannot call a method on a null-valued expression.
At D:\Leva\Work\Informatika\CSharp\My OPENSOURCE projects\OnlineShop\packages\E
ntityFramework.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 fi
le or assembly 'file:///D:\Leva\Work\Informatika\CSharp\My OPENSOURCE projects\
OnlineShop\packages\EntityFramework.6.1.3\tools\EntityFramework.PowerShell.dll'
or one of its dependencies. The system cannot find the file specified."
At D:\Leva\Work\Informatika\CSharp\My OPENSOURCE projects\OnlineShop\packages\E
ntityFramework.6.1.3\tools\EntityFramework.psm1:809 char:5
+ $domain.CreateInstanceFrom(
+ ~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ CategoryInfo : NotSpecified: (:) [], MethodInvocationException
+ FullyQualifiedErrorId : FileNotFoundException
Type 'get-help EntityFramework' to see all available Entity Framework commands.
Successfully installed 'EntityFramework 6.1.3' to OnlineShop
As you can see,there is exception.But after all,Entity Framework 6.1.3 is succesfully added to the project,in spite of exceptions.Besides when i add reference to System.Data.Entity,and try to use it in code.I can't connect to the System.Data.Entity namespace and use libraries of this namespace.Is it connected somehow to mentioned above exception,and how to fix this?
回答1:
Use EntityFramework6\Add-Migration command, microsoft have changed name of cmdmidlet
回答2:
I solved this problem by downgrading Entity Framework 6.1.3 to Entity Framework 6.1.2.Probably it is bug of last version.
回答3:
I was getting a similar error and solved by extracting all of the tools folder in the EntityFramework.6.1.3.nupkg. You can find this package in this folder:
[your solution directory]\packages\EntityFramework.6.1.3)
回答4:
I just had the same issue with EntityFramework 6.4.0 in visual studio 2019 (v16.5.4) in a .NET Framework 4.5 Project.
PM> Enable-Migrations
Exception calling "LoadFrom" with "1" argument(s): "Could not load file or assembly 'file:///C:\Users\Administrator\source\repos\InfrastructureManager\packages\EntityFramework.6.4.0\tools\EntityFramework.PowerShell.Utility.dll' or one of its dependencies. The system cannot find the file specified."
At C:\Users\Administrator\source\repos\InfrastructureManager\packages\EntityFramework.6.1.3\tools\EntityFramework.psm1:780 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 C:\Users\Administrator\source\repos\InfrastructureManager\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:///C:\Users\Administrator\source\repos\InfrastructureManager\packages\EntityFramework.6.4.0\tools\EntityFramework.PowerShell.dll' or one of its dependencies. The system cannot find the file specified."
At C:\Users\Administrator\source\repos\InfrastructureManager\packages\EntityFramework.6.1.3\tools\EntityFramework.psm1:809 char:5
+ $domain.CreateInstanceFrom(
+ ~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ CategoryInfo : NotSpecified: (:) [], MethodInvocationException
+ FullyQualifiedErrorId : FileNotFoundException
Solution was (Package Manager Console):
Uninstall-Package EntityFramework -Force
Install-Package EntityFramework -Version 6.1.2
Enable-Migrations
More and more i like open source, since this M$ 'solutions' never but never really work.
来源：https://stackoverflow.com/questions/38268979/could-not-load-file-or-assembly-tools-entityframework-powershell-utility-dll