entity-framework – 无法启用 – 迁移.引发System.BadImageForm

使用包管理器控制台,它会抛出以下内容：

PM>启用的迁移
System.BadImageFormatException：无法加载文件或程序集“MyApp”或其依赖项之一.索引未找到. (HRESULT异常：0x80131124)
文件名：’MyApp’—> System.BadImageFormatException：找不到索引. (HRESULT异常：0x80131124)
???在System.Reflection.RuntimeAssembly._nLoad(AssemblyName fileName,String codeBase,Evidence assemblySecurity,RuntimeAssembly locationHint,StackCrawlMark& stackMark,IntPtr pPrivHostBinder,Boolean throwOnFileNotFound,Boolean forIntrospection,Boolean suppressSecurityChecks)
???在System.Reflection.RuntimeAssembly.nLoad(AssemblyName fileName,Boolean suppressSecurityChecks)
???在System.Reflection.RuntimeAssembly.InternalLoadAssemblyName(AssemblyName assemblyRef,RuntimeAssembly reqAssembly,Boolean suppressSecurityChecks)
???在System.Reflection.RuntimeAssembly.InternalLoad(String assemblyString,Boolean forIntrospection)
???在System.Reflection.RuntimeAssembly.InternalLoad(String assemblyString,Boolean forIntrospection)
???在System.Reflection.Assembly.Load(String assemblyString)
???在System.Data.Entity.Migrations.Design.ToolingFacade.BaseRunner.LoadAssembly()
???at System.Data.Entity.Migrations.Design.ToolingFacade.BaseRunner.FindType [TBase](String typeName,Func2 filter,Func2 noType,Func3 multipleTypes,Func3 noTypeWithName,Func3 multipleTypesWithName)
???在System.Data.Entity.Migrations.Design.ToolingFacade.GetContextTypeRunner.RunCore()
???在System.Data.Entity.Migrations.Design.ToolingFacade.BaseRunner.Run()

Could not load file or assembly 'MyApp' or one of its dependencies. Index not found. (Exception from HRESULT: 0x80131124)

也：
1.我的默认项目(在PM CONSOLE中)是’MyApp’
2.解决方案只有’MyApp’
3.继承自DbContext的类位于“MyApp.Models”中
4.我还尝试创建一个新的解决方案,然后将粘贴的所有类复制到它,它会抛出相同的错误

怎么了？
我曾经在此项目中启用了迁移,但两天后我删除了所有迁移内容,因为它不是必需的.但现在我真的需要它们