XML Serialization Issue

[Tim Cartwright]

I recently added a new property to a base object that had a property with a
protected set. After adding the new propery to the class that inherited from
that class, I get the below error. This web service was working until this
change.

System.InvalidO perationExcepti on: Unable to generate a temporary class
(result=1).
error CS0272: The property or indexer 'USI.Data.Commo n.BizBase.IsVal id'
cannot be used in this context because the set accessor is inaccessible
error CS0272: The property or indexer 'USI.Data.Commo n.BizBase.IsVal id'
cannot be used in this context because the set accessor is inaccessible

at System.Xml.Seri alization.Compi ler.Compile(Ass embly parent, String ns,
CompilerParamet ers parameters, Evidence evidence)
at System.Xml.Seri alization.TempA ssembly.Generat eAssembly(XmlMa pping[]
xmlMappings, Type[] types, String defaultNamespac e, Evidence evidence,
CompilerParamet ers parameters, Assembly assembly, Hashtable assemblies)
at System.Xml.Seri alization.TempA ssembly..ctor(X mlMapping[] xmlMappings,
Type[] types, String defaultNamespac e, String location, Evidence evidence)
at System.Xml.Seri alization.XmlSe rializer.FromMa ppings(XmlMappi ng[]
mappings, Evidence evidence)
at
System.Web.Serv ices.Protocols. XmlReturn.GetIn itializers(Logi calMethodInfo[]
methodInfos)
at
System.Web.Serv ices.Protocols. XmlReturnWriter .GetInitializer s(LogicalMethod Info[]
methodInfos)
at System.Web.Serv ices.Protocols. MimeFormatter.G etInitializers( Type type,
LogicalMethodIn fo[] methodInfos)
at System.Web.Serv ices.Protocols. HttpServerType. .ctor(Type type)
at System.Web.Serv ices.Protocols. HttpServerProto col.Initialize( )
at System.Web.Serv ices.Protocols. ServerProtocolF actory.Create(T ype type,
HttpContext context, HttpRequest request, HttpResponse response, Boolean&
abortProcessing )

Here is a simplified version of the code :

[XmlIgnore(), SoapIgnore()]
public override bool IsValid {
get {
return true;
}
protected set {
//throw new Exception("The method or operation is not
implemented.");
}
}

As you can see I tried adding the xmlignore and the soapignore properties to
no avail. I have to override the IsValid because it is abstract as well.