Question

When reading this valid XML with Mono’s System.Xml.XmlReader I get the following error:

System.InvalidOperationException: Read by order only possible for encoded/bare format
  at System.Xml.Serialization.ClassMap.GetElement (Int32 index) [0x00000] in <filename unknown>:0 
  at System.Xml.Serialization.XmlSerializationReaderInterpreter.ReadMembers (System.Xml.Serialization.ClassMap map, System.Object ob, Boolean isValueList, Boolean readBySoapOrder) [0x00000] in <filename unknown>:0 
  at System.Xml.Serialization.XmlSerializationReaderInterpreter.ReadClassInstanceMembers (System.Xml.Serialization.XmlTypeMapping typeMap, System.Object ob) [0x00000] in <filename unknown>:0 
  at System.Xml.Serialization.XmlSerializationReaderInterpreter.ReadClassInstance (System.Xml.Serialization.XmlTypeMapping typeMap, Boolean isNullable, Boolean checkType) [0x00000] in <filename unknown>:0 
  at System.Xml.Serialization.XmlSerializationReaderInterpreter.ReadObject (System.Xml.Serialization.XmlTypeMapping typeMap, Boolean isNullable, Boolean checkType) [0x00000] in <filename unknown>:0 
  at System.Xml.Serialization.XmlSerializationReaderInterpreter.ReadObjectElement (System.Xml.Serialization.XmlTypeMapElementInfo elem) [0x00000] in <filename unknown>:0 
  at System.Xml.Serialization.XmlSerializationReaderInterpreter.ReadMembers (System.Xml.Serialization.ClassMap map, System.Object ob, Boolean isValueList, Boolean readBySoapOrder) [0x00000] in <filename unknown>:0 
  at System.Xml.Serialization.XmlSerializationReaderInterpreter.ReadClassInstanceMembers (System.Xml.Serialization.XmlTypeMapping typeMap, System.Object ob) [0x00000] in <filename unknown>:0 
  at System.Xml.Serialization.XmlSerializationReaderInterpreter.ReadClassInstance (System.Xml.Serialization.XmlTypeMapping typeMap, Boolean isNullable, Boolean checkType) [0x00000] in <filename unknown>:0 
  at System.Xml.Serialization.XmlSerializationReaderInterpreter.ReadObject (System.Xml.Serialization.XmlTypeMapping typeMap, Boolean isNullable, Boolean checkType) [0x00000] in <filename unknown>:0 
  at System.Xml.Serialization.XmlSerializationReaderInterpreter.ReadRoot (System.Xml.Serialization.XmlTypeMapping rootMap) [0x00000] in <filename unknown>:0 
  at System.Xml.Serialization.XmlSerializationReaderInterpreter.ReadRoot () [0x00000] in <filename unknown>:0 
  at System.Xml.Serialization.XmlSerializer.Deserialize (System.Xml.Serialization.XmlSerializationReader reader) [0x00000] in <filename unknown>:0 

What is the problem?

What does Read by order only possible for encoded/bare format mean in the first place?

Monodevelop 2.8.6.3 on Ubuntu 2012.04 running platform Mono / .NET 3.5
Mono JIT compiler 2.10.8.1

Answer 1

Mono crashes on <xsd:choice>

See https://bugzilla.xamarin.com/show_bug.cgi?id=2907