We have an issue with block rendering in edit mode.

We have a block which contains another block used as a property (or "local block" as defined by Joel Abrahamsson)

We are using EditAttributes() appropriately in the View to render the edit features in preview mode. However, whenever we do make a change to one of the properties of the local block in preview mode, we're receiving an error message "The block can not be displayed".

We'd expect to be able to make changes to the property in preview mode and see those changes reflect immediately as we've seen this in the past.

For example - our block which references the local block:

public class MediaBlock : BlockData
{
    [Display(
    Name = "Media Content",
    public virtual MediaContentBlock Content { get; set; }
}

The local block:

public class MediaContentBlock : SiteBlockData
{
    [Display(Name = "Test message")]
    public virtual string TestMsg{ get; set; }

}

Bog standard controller:

public class MediaBlockController : BlockController
{
    public override ActionResult Index(MediaBlock currentBlock)
    {
        return PartialView(currentBlock);
    }
}

Bog standard view:

@model MediaBlock
 x.Content)>
    @Model.Content.TestMsg

The behaviour is as follows:

1. Create the block and view it in edit mode - the block will render fine at this point.

2. Click on the block edit attribute - change the TextMsg text to something

3. Observe the behaviour: