Erro ao executar Add-Migration

Voce executou anteriormente o comando?

Enable-Migrations

Henrique Maich, boa tarde, obrigado pela ajuda. Mas após executar o comando:

PM> Enable-Migrations

Também obtive erro:

O termo 'Enable-Migrations' não é reconhecido como nome de cmdlet, função, arquivo d
e script ou programa operável. Verifique a grafia do nome ou, se um caminho tiver si
do incluído, veja se o caminho está correto e tente novamente.
Em linha:1 caractere:18
+ Enable-Migrations <<<< 
    + CategoryInfo          : ObjectNotFound: (Enable-Migrations:String) [], Comman 
   dNotFoundException
    + FullyQualifiedErrorId : CommandNotFoundException

Você esta utilizando o NuGet Package Console correto?

A instalação do EntityFramework ocorreu com exito?

Henrique Maich, boa tarde...

Você esta utilizando o NuGet Package Console correto?

Sim, é o console do NuGet Package...

A instalação do EntityFramework ocorreu com exito?

Abaixo eu coloquei todas as saídas durante a instalação e lá no final do post tem só o trecho com o erro.

INSTALAÇÃO DO SQLSERVER

Install-Package EntityFramework.MicrosoftSqlServer -Version 7.0.0-rc1-final -Pre

Resultado

Tentando coletar informações de dependências do pacote 'EntityFramework.MicrosoftSqlServer.7.0.0-rc1-final' em relação ao projeto 'EntityFrameWorkTrainee', visando '.NETFramework,Version=v4.6.2'
A coleta de informações de dependência levou 4,39 sec
Tentando resolver dependências do pacote 'EntityFramework.MicrosoftSqlServer.7.0.0-rc1-final' com DependencyBehavior 'Lowest'
Resolver as informações de dependência levou 0 ms
Resolvendo ações para instalar o pacote 'EntityFramework.MicrosoftSqlServer.7.0.0-rc1-final'
Ações resolvidas para instalar o pacote 'EntityFramework.MicrosoftSqlServer.7.0.0-rc1-final'
Recuperando o pacote 'EntityFramework.MicrosoftSqlServer 7.0.0-rc1-final' de 'NuGet feed v2'.
Adicionando pacote 'EntityFramework.MicrosoftSqlServer.7.0.0-rc1-final' à pasta 'c:\users\maxwal\documents\visual studio 2017\Projects\EntityFrameWorkTrainee\packages'
Pacote 'EntityFramework.MicrosoftSqlServer.7.0.0-rc1-final' adicionado à pasta 'c:\users\maxwal\documents\visual studio 2017\Projects\EntityFrameWorkTrainee\packages'
Pacote 'EntityFramework.MicrosoftSqlServer.7.0.0-rc1-final' adicionado a 'packages.config'
'EntityFramework.MicrosoftSqlServer 7.0.0-rc1-final' instalado com sucesso em EntityFrameWorkTrainee
Executar ações do nuget levou 533,79 ms
Tempo Decorrido: 00:00:04.9872654

INSTALAÇÃO DOS COMANDOS

Install-Package EntityFramework.Commands -Version 7.0.0-rc1-final -pre

Resultado:

Tentando coletar informações de dependências do pacote 'EntityFramework.Commands.7.0.0-rc1-final' em relação ao projeto 'EntityFrameWorkTrainee', visando '.NETFramework,Version=v4.6.2'
A coleta de informações de dependência levou 8,99 sec
Tentando resolver dependências do pacote 'EntityFramework.Commands.7.0.0-rc1-final' com DependencyBehavior 'Lowest'
Resolver as informações de dependência levou 0 ms
Resolvendo ações para instalar o pacote 'EntityFramework.Commands.7.0.0-rc1-final'
Ações resolvidas para instalar o pacote 'EntityFramework.Commands.7.0.0-rc1-final'
Recuperando o pacote 'EntityFramework.Commands 7.0.0-rc1-final' de 'NuGet feed v2'.
Recuperando o pacote 'EntityFramework.Core 7.0.0-rc1-final' de 'NuGet feed v2'.
Recuperando o pacote 'EntityFramework.Relational 7.0.0-rc1-final' de 'NuGet feed v2'.
Recuperando o pacote 'EntityFramework.Relational.Design 7.0.0-rc1-final' de 'NuGet feed v2'.
Recuperando o pacote 'Ix-Async 1.2.5' de 'NuGet feed v2'.
Recuperando o pacote 'Microsoft.Extensions.Caching.Abstractions 1.0.0-rc1-final' de 'NuGet feed v2'.
Recuperando o pacote 'Microsoft.Extensions.Caching.Memory 1.0.0-rc1-final' de 'NuGet feed v2'.
Recuperando o pacote 'Microsoft.Extensions.Configuration 1.0.0-rc1-final' de 'NuGet feed v2'.
Recuperando o pacote 'Microsoft.Extensions.Configuration.Abstractions 1.0.0-rc1-final' de 'NuGet feed v2'.
Recuperando o pacote 'Microsoft.Extensions.Configuration.Binder 1.0.0-rc1-final' de 'NuGet feed v2'.
Recuperando o pacote 'Microsoft.Extensions.DependencyInjection 1.0.0-rc1-final' de 'NuGet feed v2'.
Recuperando o pacote 'Microsoft.Extensions.DependencyInjection.Abstractions 1.0.0-rc1-final' de 'NuGet feed v2'.
Recuperando o pacote 'Microsoft.Extensions.Logging 1.0.0-rc1-final' de 'NuGet feed v2'.
Recuperando o pacote 'Microsoft.Extensions.Logging.Abstractions 1.0.0-rc1-final' de 'NuGet feed v2'.
Recuperando o pacote 'Microsoft.Extensions.OptionsModel 1.0.0-rc1-final' de 'NuGet feed v2'.
Recuperando o pacote 'Microsoft.Extensions.Primitives 1.0.0-rc1-final' de 'NuGet feed v2'.
Recuperando o pacote 'Remotion.Linq 2.0.1' de 'NuGet feed v2'.
Recuperando o pacote 'System.Collections.Immutable 1.1.36' de 'NuGet feed v2'.
Recuperando o pacote 'System.Diagnostics.DiagnosticSource 4.0.0-beta-23516' de 'NuGet feed v2'.
Recuperando o pacote 'System.Diagnostics.Tracing 4.0.0' de 'NuGet feed v2'.
Recuperando o pacote 'System.Runtime 4.0.0' de 'NuGet feed v2'.
Recuperando o pacote 'System.Threading 4.0.0' de 'NuGet feed v2'.
Adicionando pacote 'Ix-Async.1.2.5' à pasta 'c:\users\maxwal\documents\visual studio 2017\Projects\EntityFrameWorkTrainee\packages'
Pacote 'Ix-Async.1.2.5' adicionado à pasta 'c:\users\maxwal\documents\visual studio 2017\Projects\EntityFrameWorkTrainee\packages'
Pacote 'Ix-Async.1.2.5' adicionado a 'packages.config'
'Ix-Async 1.2.5' instalado com sucesso em EntityFrameWorkTrainee
Adicionando pacote 'Microsoft.Extensions.DependencyInjection.Abstractions.1.0.0-rc1-final' à pasta 'c:\users\maxwal\documents\visual studio 2017\Projects\EntityFrameWorkTrainee\packages'
Pacote 'Microsoft.Extensions.DependencyInjection.Abstractions.1.0.0-rc1-final' adicionado à pasta 'c:\users\maxwal\documents\visual studio 2017\Projects\EntityFrameWorkTrainee\packages'
Pacote 'Microsoft.Extensions.DependencyInjection.Abstractions.1.0.0-rc1-final' adicionado a 'packages.config'
'Microsoft.Extensions.DependencyInjection.Abstractions 1.0.0-rc1-final' instalado com sucesso em EntityFrameWorkTrainee
Adicionando pacote 'Microsoft.Extensions.DependencyInjection.1.0.0-rc1-final' à pasta 'c:\users\maxwal\documents\visual studio 2017\Projects\EntityFrameWorkTrainee\packages'
Pacote 'Microsoft.Extensions.DependencyInjection.1.0.0-rc1-final' adicionado à pasta 'c:\users\maxwal\documents\visual studio 2017\Projects\EntityFrameWorkTrainee\packages'
Pacote 'Microsoft.Extensions.DependencyInjection.1.0.0-rc1-final' adicionado a 'packages.config'
'Microsoft.Extensions.DependencyInjection 1.0.0-rc1-final' instalado com sucesso em EntityFrameWorkTrainee
Adicionando pacote 'Microsoft.Extensions.Logging.Abstractions.1.0.0-rc1-final' à pasta 'c:\users\maxwal\documents\visual studio 2017\Projects\EntityFrameWorkTrainee\packages'
Pacote 'Microsoft.Extensions.Logging.Abstractions.1.0.0-rc1-final' adicionado à pasta 'c:\users\maxwal\documents\visual studio 2017\Projects\EntityFrameWorkTrainee\packages'
Pacote 'Microsoft.Extensions.Logging.Abstractions.1.0.0-rc1-final' adicionado a 'packages.config'
'Microsoft.Extensions.Logging.Abstractions 1.0.0-rc1-final' instalado com sucesso em EntityFrameWorkTrainee
Adicionando pacote 'Microsoft.Extensions.Logging.1.0.0-rc1-final' à pasta 'c:\users\maxwal\documents\visual studio 2017\Projects\EntityFrameWorkTrainee\packages'
Pacote 'Microsoft.Extensions.Logging.1.0.0-rc1-final' adicionado à pasta 'c:\users\maxwal\documents\visual studio 2017\Projects\EntityFrameWorkTrainee\packages'
Pacote 'Microsoft.Extensions.Logging.1.0.0-rc1-final' adicionado a 'packages.config'
'Microsoft.Extensions.Logging 1.0.0-rc1-final' instalado com sucesso em EntityFrameWorkTrainee
Adicionando pacote 'Microsoft.Extensions.Primitives.1.0.0-rc1-final' à pasta 'c:\users\maxwal\documents\visual studio 2017\Projects\EntityFrameWorkTrainee\packages'
Pacote 'Microsoft.Extensions.Primitives.1.0.0-rc1-final' adicionado à pasta 'c:\users\maxwal\documents\visual studio 2017\Projects\EntityFrameWorkTrainee\packages'
Pacote 'Microsoft.Extensions.Primitives.1.0.0-rc1-final' adicionado a 'packages.config'
'Microsoft.Extensions.Primitives 1.0.0-rc1-final' instalado com sucesso em EntityFrameWorkTrainee
Adicionando pacote 'Microsoft.Extensions.Caching.Abstractions.1.0.0-rc1-final' à pasta 'c:\users\maxwal\documents\visual studio 2017\Projects\EntityFrameWorkTrainee\packages'
Pacote 'Microsoft.Extensions.Caching.Abstractions.1.0.0-rc1-final' adicionado à pasta 'c:\users\maxwal\documents\visual studio 2017\Projects\EntityFrameWorkTrainee\packages'
Pacote 'Microsoft.Extensions.Caching.Abstractions.1.0.0-rc1-final' adicionado a 'packages.config'
'Microsoft.Extensions.Caching.Abstractions 1.0.0-rc1-final' instalado com sucesso em EntityFrameWorkTrainee
Adicionando pacote 'Microsoft.Extensions.Configuration.Abstractions.1.0.0-rc1-final' à pasta 'c:\users\maxwal\documents\visual studio 2017\Projects\EntityFrameWorkTrainee\packages'
Pacote 'Microsoft.Extensions.Configuration.Abstractions.1.0.0-rc1-final' adicionado à pasta 'c:\users\maxwal\documents\visual studio 2017\Projects\EntityFrameWorkTrainee\packages'
Pacote 'Microsoft.Extensions.Configuration.Abstractions.1.0.0-rc1-final' adicionado a 'packages.config'
'Microsoft.Extensions.Configuration.Abstractions 1.0.0-rc1-final' instalado com sucesso em EntityFrameWorkTrainee
Adicionando pacote 'Microsoft.Extensions.Configuration.1.0.0-rc1-final' à pasta 'c:\users\maxwal\documents\visual studio 2017\Projects\EntityFrameWorkTrainee\packages'
Pacote 'Microsoft.Extensions.Configuration.1.0.0-rc1-final' adicionado à pasta 'c:\users\maxwal\documents\visual studio 2017\Projects\EntityFrameWorkTrainee\packages'
Pacote 'Microsoft.Extensions.Configuration.1.0.0-rc1-final' adicionado a 'packages.config'
'Microsoft.Extensions.Configuration 1.0.0-rc1-final' instalado com sucesso em EntityFrameWorkTrainee
Adicionando pacote 'Microsoft.Extensions.Configuration.Binder.1.0.0-rc1-final' à pasta 'c:\users\maxwal\documents\visual studio 2017\Projects\EntityFrameWorkTrainee\packages'
Pacote 'Microsoft.Extensions.Configuration.Binder.1.0.0-rc1-final' adicionado à pasta 'c:\users\maxwal\documents\visual studio 2017\Projects\EntityFrameWorkTrainee\packages'
Pacote 'Microsoft.Extensions.Configuration.Binder.1.0.0-rc1-final' adicionado a 'packages.config'
'Microsoft.Extensions.Configuration.Binder 1.0.0-rc1-final' instalado com sucesso em EntityFrameWorkTrainee
Adicionando pacote 'Microsoft.Extensions.OptionsModel.1.0.0-rc1-final' à pasta 'c:\users\maxwal\documents\visual studio 2017\Projects\EntityFrameWorkTrainee\packages'
Pacote 'Microsoft.Extensions.OptionsModel.1.0.0-rc1-final' adicionado à pasta 'c:\users\maxwal\documents\visual studio 2017\Projects\EntityFrameWorkTrainee\packages'
Pacote 'Microsoft.Extensions.OptionsModel.1.0.0-rc1-final' adicionado a 'packages.config'
'Microsoft.Extensions.OptionsModel 1.0.0-rc1-final' instalado com sucesso em EntityFrameWorkTrainee
Adicionando pacote 'Microsoft.Extensions.Caching.Memory.1.0.0-rc1-final' à pasta 'c:\users\maxwal\documents\visual studio 2017\Projects\EntityFrameWorkTrainee\packages'
Pacote 'Microsoft.Extensions.Caching.Memory.1.0.0-rc1-final' adicionado à pasta 'c:\users\maxwal\documents\visual studio 2017\Projects\EntityFrameWorkTrainee\packages'
Pacote 'Microsoft.Extensions.Caching.Memory.1.0.0-rc1-final' adicionado a 'packages.config'
'Microsoft.Extensions.Caching.Memory 1.0.0-rc1-final' instalado com sucesso em EntityFrameWorkTrainee
Adicionando pacote 'Remotion.Linq.2.0.1' à pasta 'c:\users\maxwal\documents\visual studio 2017\Projects\EntityFrameWorkTrainee\packages'
Pacote 'Remotion.Linq.2.0.1' adicionado à pasta 'c:\users\maxwal\documents\visual studio 2017\Projects\EntityFrameWorkTrainee\packages'
Pacote 'Remotion.Linq.2.0.1' adicionado a 'packages.config'
'Remotion.Linq 2.0.1' instalado com sucesso em EntityFrameWorkTrainee
Adicionando pacote 'System.Collections.Immutable.1.1.36' à pasta 'c:\users\maxwal\documents\visual studio 2017\Projects\EntityFrameWorkTrainee\packages'
Pacote 'System.Collections.Immutable.1.1.36' adicionado à pasta 'c:\users\maxwal\documents\visual studio 2017\Projects\EntityFrameWorkTrainee\packages'
Pacote 'System.Collections.Immutable.1.1.36' adicionado a 'packages.config'
'System.Collections.Immutable 1.1.36' instalado com sucesso em EntityFrameWorkTrainee
Adicionando pacote 'EntityFramework.Core.7.0.0-rc1-final' à pasta 'c:\users\maxwal\documents\visual studio 2017\Projects\EntityFrameWorkTrainee\packages'
Pacote 'EntityFramework.Core.7.0.0-rc1-final' adicionado à pasta 'c:\users\maxwal\documents\visual studio 2017\Projects\EntityFrameWorkTrainee\packages'
Pacote 'EntityFramework.Core.7.0.0-rc1-final' adicionado a 'packages.config'
'EntityFramework.Core 7.0.0-rc1-final' instalado com sucesso em EntityFrameWorkTrainee
Adicionando pacote 'System.Diagnostics.Tracing.4.0.0' à pasta 'c:\users\maxwal\documents\visual studio 2017\Projects\EntityFrameWorkTrainee\packages'
Pacote 'System.Diagnostics.Tracing.4.0.0' adicionado à pasta 'c:\users\maxwal\documents\visual studio 2017\Projects\EntityFrameWorkTrainee\packages'
Pacote 'System.Diagnostics.Tracing.4.0.0' adicionado a 'packages.config'
'System.Diagnostics.Tracing 4.0.0' instalado com sucesso em EntityFrameWorkTrainee
Adicionando pacote 'System.Runtime.4.0.0' à pasta 'c:\users\maxwal\documents\visual studio 2017\Projects\EntityFrameWorkTrainee\packages'
Pacote 'System.Runtime.4.0.0' adicionado à pasta 'c:\users\maxwal\documents\visual studio 2017\Projects\EntityFrameWorkTrainee\packages'
Pacote 'System.Runtime.4.0.0' adicionado a 'packages.config'
'System.Runtime 4.0.0' instalado com sucesso em EntityFrameWorkTrainee
Adicionando pacote 'System.Threading.4.0.0' à pasta 'c:\users\maxwal\documents\visual studio 2017\Projects\EntityFrameWorkTrainee\packages'
Pacote 'System.Threading.4.0.0' adicionado à pasta 'c:\users\maxwal\documents\visual studio 2017\Projects\EntityFrameWorkTrainee\packages'
Pacote 'System.Threading.4.0.0' adicionado a 'packages.config'
'System.Threading 4.0.0' instalado com sucesso em EntityFrameWorkTrainee
Adicionando pacote 'System.Diagnostics.DiagnosticSource.4.0.0-beta-23516' à pasta 'c:\users\maxwal\documents\visual studio 2017\Projects\EntityFrameWorkTrainee\packages'
Pacote 'System.Diagnostics.DiagnosticSource.4.0.0-beta-23516' adicionado à pasta 'c:\users\maxwal\documents\visual studio 2017\Projects\EntityFrameWorkTrainee\packages'
Pacote 'System.Diagnostics.DiagnosticSource.4.0.0-beta-23516' adicionado a 'packages.config'
'System.Diagnostics.DiagnosticSource 4.0.0-beta-23516' instalado com sucesso em EntityFrameWorkTrainee
Adicionando pacote 'EntityFramework.Relational.7.0.0-rc1-final' à pasta 'c:\users\maxwal\documents\visual studio 2017\Projects\EntityFrameWorkTrainee\packages'
Pacote 'EntityFramework.Relational.7.0.0-rc1-final' adicionado à pasta 'c:\users\maxwal\documents\visual studio 2017\Projects\EntityFrameWorkTrainee\packages'
Pacote 'EntityFramework.Relational.7.0.0-rc1-final' adicionado a 'packages.config'
'EntityFramework.Relational 7.0.0-rc1-final' instalado com sucesso em EntityFrameWorkTrainee
Adicionando pacote 'EntityFramework.Relational.Design.7.0.0-rc1-final' à pasta 'c:\users\maxwal\documents\visual studio 2017\Projects\EntityFrameWorkTrainee\packages'
Pacote 'EntityFramework.Relational.Design.7.0.0-rc1-final' adicionado à pasta 'c:\users\maxwal\documents\visual studio 2017\Projects\EntityFrameWorkTrainee\packages'
Pacote 'EntityFramework.Relational.Design.7.0.0-rc1-final' adicionado a 'packages.config'
'EntityFramework.Relational.Design 7.0.0-rc1-final' instalado com sucesso em EntityFrameWorkTrainee
Adicionando pacote 'EntityFramework.Commands.7.0.0-rc1-final' à pasta 'c:\users\maxwal\documents\visual studio 2017\Projects\EntityFrameWorkTrainee\packages'
Pacote 'EntityFramework.Commands.7.0.0-rc1-final' adicionado à pasta 'c:\users\maxwal\documents\visual studio 2017\Projects\EntityFrameWorkTrainee\packages'
Pacote 'EntityFramework.Commands.7.0.0-rc1-final' adicionado a 'packages.config'
Executando o arquivo de script 'c:\users\maxwal\documents\visual studio 2017\Projects\EntityFrameWorkTrainee\packages\EntityFramework.Commands.7.0.0-rc1-final\tools\init.ps1'
Where-Object : Não é possível associar o parâmetro 'FilterScript'. Não é possível co
nverter o valor "Name" do tipo "System.String" no tipo "System.Management.Automation
.ScriptBlock".
Em C:\users\maxwal\documents\visual studio 2017\Projects\EntityFrameWorkTrainee\pack
ages\EntityFramework.Commands.7.0.0-rc1-final\tools\init.ps1:3 caractere:19
+ if (Get-Module | ? <<<<  Name -eq EntityFramework) {
    + CategoryInfo          : InvalidArgument: (:) [Where-Object], ParameterBinding 
   Exception
    + FullyQualifiedErrorId : CannotConvertArgumentNoMessage,Microsoft.PowerShell.C 
   ommands.WhereObjectCommand

Join-Path : Não é possível associar o argumento ao parâmetro 'Path' porque ele é nul
o.
Em C:\users\maxwal\documents\visual studio 2017\Projects\EntityFrameWorkTrainee\pack
ages\EntityFramework.Commands.7.0.0-rc1-final\tools\init.ps1:7 caractere:25
+ Import-Module (Join-Path <<<<  $PSScriptRoot EntityFramework.psd1) -DisableNameChe
cking
    + CategoryInfo          : InvalidData: (:) [Join-Path], ParameterBindingValidat 
   ionException
    + FullyQualifiedErrorId : ParameterArgumentValidationErrorNullNotAllowed,Micros 
   oft.PowerShell.Commands.JoinPathCommand

Executando o arquivo de script 'c:\users\maxwal\documents\visual studio 2017\Projects\EntityFrameWorkTrainee\packages\EntityFramework.Commands.7.0.0-rc1-final\tools\install.ps1'

Type 'get-help EntityFramework' to see all available Entity Framework commands.

'EntityFramework.Commands 7.0.0-rc1-final' instalado com sucesso em EntityFrameWorkTrainee
Executar ações do nuget levou 15,03 sec
Tempo Decorrido: 00:00:24.2987420

Esse último comando teve um erro no processo de instalação, como pode ver no resultado completo acima, mas vou destacar o erro abaixo para facilitar a visualização:

Where-Object : Não é possível associar o parâmetro 'FilterScript'. Não é possível co
nverter o valor "Name" do tipo "System.String" no tipo "System.Management.Automation
.ScriptBlock".
Em C:\users\maxwal\documents\visual studio 2017\Projects\EntityFrameWorkTrainee\pack
ages\EntityFramework.Commands.7.0.0-rc1-final\tools\init.ps1:3 caractere:19
+ if (Get-Module | ? <<<<  Name -eq EntityFramework) {
    + CategoryInfo          : InvalidArgument: (:) [Where-Object], ParameterBinding 
   Exception
    + FullyQualifiedErrorId : CannotConvertArgumentNoMessage,Microsoft.PowerShell.C 
   ommands.WhereObjectCommand

Join-Path : Não é possível associar o argumento ao parâmetro 'Path' porque ele é nul
o.
Em C:\users\maxwal\documents\visual studio 2017\Projects\EntityFrameWorkTrainee\pack
ages\EntityFramework.Commands.7.0.0-rc1-final\tools\init.ps1:7 caractere:25
+ Import-Module (Join-Path <<<<  $PSScriptRoot EntityFramework.psd1) -DisableNameChe
cking
    + CategoryInfo          : InvalidData: (:) [Join-Path], ParameterBindingValidat 
   ionException
    + FullyQualifiedErrorId : ParameterArgumentValidationErrorNullNotAllowed,Micros 
   oft.PowerShell.Commands.JoinPathCommand

Opa. dei uma pesquisada e achei aqui no forum mesmo a seguinte soluçao postada pelo Erick https://cursos.alura.com.br/forum/topico-duvida-no-ex-1-da-aula-1-comecando-com-entity-framework-20389

"Consegui resolver o problema fazendo umas pesquisas mais detalhadas. Para quem estiver com o mesmo problema, recomendo procurar pela atualização do Windows PowerShell para a versão 3.0, seguindo a sua respectiva versão do Windows também. Se a atualização não for feita, vai ocorrer esse erro no console do Nuget e comandos como o Add-Migrations não estará disponível..."

Pesquisando um pouco no Google https://www.microsoft.com/en-us/download/details.aspx?id=34595

Ve ai se resolve seu problema

Henrique Maich, você estava certo! Ao atualizar Windows PowerShell para a versão 3.0 por meio do link:

 https://www.microsoft.com/en-us/download/details.aspx?id=34595

Foi possível executar o código abaixo sem erro:

Install-Package EntityFramework.Commands -Version 7.0.0-rc1-final -pre

Add-Migration criaUsuario

Problema resolvido... Obrigado!!!