>>I've never used AutoMapper but you seem to be mapping from a small object to a larger one with additional properties - do you have it the wrong way around ?
>>Or do you have some rule in the map which tells it how to populate ItemType ?
>
>In order to resolve that problem I had to add ItemType to the model as well.

Adding a member to the source to get round the problem doesn't sound right. Would adding the

.ForMember(dest => dest.ItemType, opt => opt.Ignore());

to your CreateMap method work instead ?

> I don't know why all other properties were successfully ignored in run-time and this one caused troubles.

Don't know why either. If you try 'Mapper.AssertConfigurationIsValid();' I think you will find that it will complain about all unmapped members in the destination class.

Can you post the two class definition :?

Update: I see in the original exception a 'ItemType.ItemType' and there is an ItemType property in C# RepeaterItem. Maybe AutoMapper is confused by this. Do you get the exception if you change the name ?