errorThrown string provided in ParseError from the
fail Promise callback.
errorThrown: string; // read-only
if no string was initially provided, then null, otherwise that same string.
This string value is one of the initially-provided parameters to the ParseError static method, and is kept
as a property. The value of
errorThrown is also available from
jqXHR.statusText, which is not to be confused with
statusText string or the StatusText property, as those do not exist as properties within the
Medical Web Viewer .NET