Adding breadcrumb to template, or any page for that matter t

An absolute beauty  or an error:

Index must be within the bounds of the List.
Parameter name: index

[ArgumentOutOfRangeException: Index must be within the bounds of the List.
Parameter name: index]
System.Collections.ObjectModel.Collection`1.Insert(Int32 index, T item) +14406439
Telerik.Sitefinity.Web.UI.ZoneEditor.ProcessMisplacedControls() +1501
Telerik.Sitefinity.Web.UI.ZoneEditor.CreateChildControls() +129

And once I am in this error  for a template, it renders it useless.

Firstly, what on earth is going on? Why would adding a breadcrumb result in this? Please note, this also appears on a normal page and appears to happen when I add group pages to the breadcrumb.

Why isn't there a revision history for the templates? That way if this happened again, I'd be able to revert back to the working one without hitting the yellow stack of doom.. 

And now, after disassociating the pages with the template, I go to delete the 'broken' template and get an "Object reference not set to an instance of an object".

Superb. Absolutely belting.