The issue is that I have something like:

public IDictionary<string,string> Attr { get; } #Notice no setter!
And in the mapping, I didn't define an access strategy.


Here is the exception:

Error 1 TestCase 'NHibernate.Generics.Tests.EntityListTests.CantAddDuplicateValue'
failed: System.ArgumentNullException : Value cannot be null.
Parameter name: methodInfo
   at System.Reflection.Emit.DynamicILGenerator.EmitCall(OpCode opcode, MethodInfo methodInfo, Type[] optionalParameterTypes)
   at NHibernate.Property.BasicSetter.Emit(ILGenerator il) in C:\Code\NHibernate\nhibernate\src\NHibernate\Property\BasicSetter.cs:line 94
   at NHibernate.Bytecode.Lightweight.ReflectionOptimizer.GenerateSetPropertyValuesMethod(IGetter[] getters, ISetter[] setters) in C:\Code\NHibernate\nhibernate\src\NHibernate\Bytecode\Lightweight\ReflectionOptimizer.cs:line 212
   at NHibernate.Bytecode.Lightweight.ReflectionOptimizer..ctor(Type mappedType, IGetter[] getters, ISetter[] setters) in C:\Code\NHibernate\nhibernate\src\NHibernate\Bytecode\Lightweight\ReflectionOptimizer.cs:line 47
   at NHibernate.Bytecode.Lightweight.BytecodeProviderImpl.GetReflectionOptimizer(Type mappedClass, IGetter[] getters, ISetter[] setters) in C:\Code\NHibernate\nhibernate\src\NHibernate\Bytecode\Lightweight\BytecodeProviderImpl.cs:line 40
   at NHibernate.Persister.Entity.AbstractEntityPersister..ctor(PersistentClass persistentClass, ISessionFactoryImplementor factory) in C:\Code\NHibernate\nhibernate\src\NHibernate\Persister\Entity\AbstractEntityPersister.cs:line 820
   at NHibernate.Persister.Entity.SingleTableEntityPersister..ctor(PersistentClass model, ISessionFactoryImplementor factory, IMapping mapping) in C:\Code\NHibernate\nhibernate\src\NHibernate\Persister\Entity\SingleTableEntityPersister.cs:line 771
   at NHibernate.Persister.PersisterFactory.CreateClassPersister(PersistentClass model, ISessionFactoryImplementor factory, IMapping cfg) in C:\Code\NHibernate\nhibernate\src\NHibernate\Persister\PersisterFactory.cs:line 51
   at NHibernate.Impl.SessionFactoryImpl..ctor(Configuration cfg, IMapping mapping, Settings settings) in C:\Code\NHibernate\nhibernate\src\NHibernate\Impl\SessionFactoryImpl.cs:line 169
   at NHibernate.Cfg.Configuration.BuildSessionFactory() in C:\Code\NHibernate\nhibernate\src\NHibernate\Cfg\Configuration.cs:line 1016
   at NHibernate.Generics.Tests.DatabaseTests.CreateSessionFactory() in C:\Code\nqa\NHibernate.Generics\NHibernate.Generics.Tests\GenericWrapperAccessorTests.cs:line 34
   at NHibernate.Generics.Tests.EntityListTests.SetUp() in C:\Code\nqa\NHibernate.Generics\NHibernate.Generics.Tests\EntityListTests.cs:line 20 C:\Code\NHibernate\nhibernate\src\NHibernate\Property\BasicSetter.cs 94